The study makes an attempt to estimate the impact of becoming member of dairy co-operative society (DCS) on adoption of improved and production augmenting farm practices such as fodder cultivation, adoption of artificial insemination (AI) and concentrate feeding among dairy farmers in Assam. As simple comparison between members and non-members of DCS on the impact indicators may be embedded with selection bias and may not give accurate estimates, the study has used propensity score matching to address selection bias based on observed covariates. Relying on information from a sample of 202 smallholder dairy farmers and by estimating the average treatment effects on the treated (ATT), the study has shown that members of DCS are significantly found to practise fodder cultivation, adopt more AI and feed more amount of concentrates to their animal. Given that these impact indicators of becoming members of DCS may have productivity enhancing effect, the co-operative system of dairying in the state needs to be strengthened to develop the dairy sector of the state.