Climate change is a global challenge affecting human health, livelihood, and food security, and poses a serious threat to agriculture. Adaptation measures are needed to mitigate climate change impacts. Social capital offers a perspective on differences in adaptation to climate change. Nevertheless, the fundamental role of social capital in agricultural adaptation isn’t fully understood. Therefore, this study investigates how social networks, norms, participation, trust, solidarity, beliefs and risk perception affect adaptation among Iranian farmers. Survey data were collected from 250 farmers randomly selected in Susangerd city, Khuzestan Province, Iran. An integrated model combining social capital, beliefs, and risk perceptions is used. Structural equation modelling results show the model explained 69% of the variance in adaptation behaviour and 66% and 40% of the variances in risk perception and climate beliefs, respectively. Such results demonstrate the robustness of the model in predicting adaptation strategies. Based on the findings, social solidarity and climate beliefs were the most effective predictors of risk perception, while farmers’ social networks were the most important predictors of behaviour. This study, by confirming the importance of social capital on the farmers’ beliefs, risk understanding and adaptation behaviour, offers suggestions for fostering and implementing more practical adaptation strategies.