Climate Smart Agriculture (CSA) represents a progressive approach to the sustainable management of agricultural resources, playing a critical role in enhancing productivity, reducing operational costs, and mitigating the impacts of climate change. Recognizing the significance of CSA in rice cultivation, this study investigates the factors influencing the adoption of CSA practices among rice farmers in Shushtar County, Khuzestan Province, Iran. The theoretical framework was grounded in Protection Motivation Theory (PMT), with two additional behavioral constructs—social norms (SN) and habits—integrated to enrich the model. Data were collected via a structured questionnaire and analyzed using structural equation modeling. Findings revealed that the original PMT framework accounted for 57.9 % of the variance in CSA adoption. Key constructs—perceived severity (PS), perceived vulnerability (PV), response cost (CR), response efficacy (RE), and self-efficacy (SE)—all demonstrated significant influence. Notably, the extended model incorporating SN and habits improved explanatory power by an additional 22 %, underscoring the relevance of social and behavioral dimensions in shaping farmer decisions. Among all variables, perceived vulnerability and response efficacy emerged as the most influential factors. Based on these insights, it is recommended that policymakers prioritize initiatives that raise awareness of climate-related risks and enhance farmers’ understanding of their vulnerability. Such efforts can foster greater engagement with CSA practices and support sustainable agricultural development in climate-sensitive regions.