The management of common-pool resources (CPR) like fisheries has long been discussed in economics. The association of CPR with degradation and poor economic performance is well known due to excess harvests and poor management. The incentives faced by a CPR user create a dilemma. Users who limit their catch, if others do not; lose. And if no one limits his catch, everyone loses. Hardin’s (1958) “Tragedy of the Commons” still applies in many situations today. However, contrary to Hardin, there exists evidence that common management or self-governance can overcome these incentives. Under self-governance, user groups take control of the CPR to improve the economic viability of the resource (Ostrom 1990; Dietz et al. 2003). The self-governance of a CPR is successful if the users develop solutions by themselves, aligning extraction rates with resource productivity to achieve a common benefit, and developing resource-specific rules that overcome the problems of free riders and opportunistic behavior (Ostrom 2005). CPR users, due the daily use of the resource, have a “solid” knowledge of the situation, which is critical for successful management. Successful cases of self-governance have been documented around the world (see Ostrom 1990; Townsend and Sutton 2008). Study of these cases has been useful to identify the characteristics of “successful” CPR management regimes. However, our ability to predict when and where self-governance is most likely to be successful is still limited. This research reviews the theoretical framework regarding the conditions required for successful self-governance for the management (SGM) of a CPR. Then we propose a method to assess the potential for SGM based on the perceptions of the CPR users’ group and their predisposition toward SGM. Finally, we test our approach in a small-scale fishery in the north side of Mexico, offering insights about whether or not a change in governance is feasible and desirable in the study site. Knowing ex-ante the likelihood that SGM will succeed may save resources and direct the effort to an efficient management of the CPR. Governments and private entities spend effort and scarce resources to regulate environmental issues, and in many cases the implementation of policies is not effective. For example, fisheries have a long history of overexploitation that has reduced the ocean's capacity to provide food, preserve water quality and recover from perturbations (Worm et al. 2009). In many cases, SGM may offer an improvement over traditional regulatory approaches. An ex-ante assessment of the potential for SGM would provide valuable information for policy makers seeking strategies for CPR management. Our model is based on the six conditions (OCs) identified by Ostrom (1990). (1) ‘most users’ conclude that they will be harmed if they do not adopt new rules. (2) ‘most. users’ conclude that they will be affected in a similar way by the new rules, (3) ‘most users’ highly value continuing the activity, (4) users share generalized norms of reciprocity and trust, (5) users face low monitoring and enforcement cost, (6) users are a small and stable group. The basic proposition is that the probability of a community successfully adopting SGM is a function of the six conditions over all the CPR users’ communities. Each of the OCs, however, is actually a function of the perspectives of the users that make up the community. The challenge for ex-ante evaluation is that OCs can´t be directly observed. To overcome this challenge we developed a series of questions, used to create an index that is a function of the responses to such questions question on each condition. To arrive at a valid set of questions, each OC is expressed the language of the CPR user in a survey administered in the summer of 2010. It was pretested in two focus groups, one with students of Universidad Juarez of Durango and another with fishers of Francisco Zarco, another lake in the region. A group of biology students were hired as enumerators to conduct most of the surveys. To increase the response rate, each fisher received a compensation of 50 Mexican pesos (about 4 US dollars), and a prize from a random drawing at the end of the survey. From a total of 148 fishers registered in the three cooperatives, only about 100 were active at the time of the survey. We interviewed 111 individuals, and then our survey is basically a census. After checking for validity and reliability, the final database was reduced to 74 observations. Using the responses of 74 of the LCR fishers, we evaluate the predisposition of the LCR fishers toward SGM based on the six OCs. Our result indicates a high predisposition towards SGM. We find a predisposition of the LCR fishers toward SGM. The strongest measure was that indicating the extent to which users believe that rules affect all fishers similarly. The weakest indicator was regarding the size stability of the fishers’ group. Overall, our measures were consistent with the additional interviews and opinions of leaders and stakeholders of the three LCR fishing communities. Several limitations should be emphasized. The most significant is the lack of a true validity measure. We do not observe ex-post whether SGM was pursued or successful, therefore we do not have strong evidence that answering OCs favor SGM or not. Although Ostrom and others have studied the idea of predicting outcomes for the management of CPR, we are unaware of any attempt to make a systematic ex-ante assessment based on Ostrom’s six conditions. Hence, there has not been an opportunity to compare a measure of a community’s predisposition toward SGM to the outcome over time, which is what would be needed to establish the true validity of such an ex-ante measure. Because of our inability to test for validity, our approach does not yield clear guidance for policy. Fishers’ perspectives might lead to a favorable environment for SGM, but it does not indicate they will adopt self-governance. Finally, as expected in ex-ante analysis, at the time of the survey we did not have specific rules to show fishers the form that SGM might take in the fishery. It increases the level of uncertainty and may affect the responses of the fishers. Despite these caveats, this approach could be valuable. In some cases CPR users have received help from the government officials by giving technical inputs and/or speeding and control the early stages of the process (Townsend 2008). In other cases CPR users and government share the management. In either case, having an indication of whether the policy can work and the dimensions that might require the most attention could save time and money, valuable inputs in the policy making process. The approach that we propose is built on the solid foundation of Ostrom’ work, which distills the experiences in a large set CPRs around the globe. An ex-ante assessment would not only help communities and policy makers in each application, but as it is replicated in more systems, it will provide a valuable baseline that can greatly help in our understanding of the relationship between ex-ante conditions and ex-post success for the management of common-pool resources.