Values held in agricultural extension systems determine which extension goals can be reached. Globally changing socio-ecological contexts require a paradigm shift in agricultural extension systems from a top-down approach dominated by instrumental values to achieve the primary goal of increasing yields, to a more site-specific relational and participatory approach that induces locally adaptive use of sustainable agricultural practices. A literature review was conducted to understand how relational values in farmer-to-farmer extension align with participatory agricultural extension systems. Relevance, trust, and place attachment are the main relational values expressed in farmer-to-farmer extension where participatory processes incorporate farmers' livelihood outcomes in the transformational goals of agricultural extension. Recognizing and strengthening the relational values in farmer-to-farmer extension, based on different contexts, will likely support the development of locally adapted knowledge and innovations, and provide a basic rationale for building communication strategies, colearning, and supporting behavioral change of all agricultural extension actors.