Public–private partnerships constitute a new mode of operation in many fields of development, including the development of innovation in developing-country agriculture. Capacities to identify opportunities, develop common interests, and negotiate commitments are prerequisites for successful public–private partnerships. Yet, many public–private partnerships fail due to lack of both skills among the partnering agents and efforts to strengthen these skills. The International Service for National Agricultural Research--on its own from 2002 until 2003, and as a division of the International Food Policy Research Institute thereafter--has studied 124 public–private partnerships in agriculture in nine Latin American countries through its initiative on public–private partnerships for Agro-Industrial Research in Latin America, (Hartwich et al. 2005). The project also supported processes of partnership building in seven agricultural production chains in Costa Rica, the Dominican Republic, Ecuador, and El Salvador by holding awareness-building workshops, mapping agrichain development opportunities, undertaking chain analysis, identifying common interests, negotiating and designing partnerships, and supporting the development of partnership agreements. Support was also given in documenting the above meetings to ensure that proposals were developed and formal agreements established. In all cases, partners sought additional external resources to complement the contributions of the partners. This paper examines these seven cases of public–private partnership building in which private-sector companies, producer associations, and research organizations engage in collaboration for the purpose of developing innovations in agricultural production and value chains. The paper considers different points of entry to partnership building, emulating best practices. The paper describes (a) how common interests among multiple stakeholders have been identified; (b) how partners have been motivated to participate in partnerships; (c) how the roles of different brokers within or outside the partnerships have fostered partnership development; and (d) how the contributions of partners have been negotiated to ensure that partnership arrangements are in alignment with the interests of the partners, their capacities, and the prevailing technological and market opportunities. The paper targets policymakers and administrators in agricultural development, and collaborators in research and innovation projects who are interested in issues of how best to build partnerships among public and private agents. In an innovation systems context, capacity strengthening to build partnerships can target three different levels: the partners, their relationships, or the overall network or system within which partnerships operate. The study adopted a flexible and generic approach to understanding partnership building, distinguishing five main phases: identification of common interests and objectives, negotiation and design, implementation, monitoring and evaluation, and termination or amplification. The results suggest that public–private partnerships for innovation are justified when addressing a problem or capitalizing on an opportunity that requires collective action or the pooling of innovative capacity. Capacity strengthening in partnership building can lead to more viable partnerships that take social and development needs into account. Public-sector promoting agents play a crucial role in building partnerships, particularly in order to motivate agri-chain actors, build trust among partners, and provide credibility to such initiatives. Gradually, as partnerships are formalized, the need for leadership by the partners themselves comes to the fore. Results also show, first, that capacity strengthening efforts directed at partnership building profit from sound analysis of market and technological opportunities in the context of respective agri-chains and, second, that identifying and exploring common interests among partners is an important foundation for partnership commitment. Finally, partnerships cannot be established as a quick fix but rather require cautious organizational development. The facilitation of the partnering process in the seven cases studied prompts six main conclusions: 1. Capacity strengthening in partnership building is specific to the value chains and actors it involves. The value chain is an appropriate context for analyzing opportunities for innovation in areas of common interest that can best be exploited through public–private collaboration. 2. Capacity strengthening for partnership building goes beyond traditional training to include horizontal learning among the partners; it a continuous process that does not suit a one-size fits all approach and requires that needs be identified taking all partners into consideration. 3. Determining when to enter into a partnership depends on the partners’ analytical skills and the information available on technological and market opportunities; participation in diagnostic exercises strengthens the capacity of partners to enter into present and future partnerships. 4. The choice of appropriate capacity strengthening measures depends on the existing level of cohesion among the potential partners; for example, awareness building may not be necessary if talks about potential collaboration are already occurring. The possible entry points for partnership-building measures need to be considered to enable common themes and objectives to be identified. The “chain mapping exercise,” for example, provides opportunities for key stakeholders and partners to be identified. 5. Strengthening partnership-building capacity should predominantly focus on identifying and exploring common interests among potential partners through a variety of tools that help clarify interests in terms of technology development, production, and sales. If partners do not become seriously interested in pursuing the partnership, they will not attach the necessary importance to its planning. Third-party catalyzing agents are necessary to bring partners together, motivate them, provide information, and organize space for negotiations. 6. It is important to have at least one visionary leader among the partners, be it in the private sector or in the public research community. The leader supplies the capacity for sectoral analysis in the partnership and can help to clarify and communicate the advantages the partnership offers. The leader is also important in motivating and attracting potential partners. The internal leader may also eventually take over the initiative from the external promoter, but a gradual transfer process is the most successful option.