Coconut is a vital plantation crop sustaining millions of rural households in India, yet productivity and profitability remain constrained by ageing palms, fragmented holdings, pest and disease pressures and weak value chains. It is becoming more widely acknowledged that farmers can overcome these obstacles by engaging in entrepreneurial behaviour, which is characterised by innovativeness, risk orientation, planning and market orientation. The Theory of Planned Behaviour (TPB) was used as the analytical framework in this study to evaluate the entrepreneurial behaviour of coconut farmers in Krishnagiri district of Tamil Nadu. A structured interview schedule was used to gather data from 120 randomly chosen farmers and analysis of moment structures (AMOS)'s confirmatory factor analysis (CFA) and structural equation modelling (SEM) were used to test the extended TPB model. The findings of the study validate the applicability of TPB in perennial cash crops and offer actionable insights for policy and extension. The constructs showed high internal reliability (Cronbach’s α > 0.70) and acceptable fit indices for the measurement and structural models. Path analysis showed that behavioural intention (BI) significantly predicted actual entrepreneurial behaviour (β = 0.832, p < 0.001), while perceived behavioural control (PBC) had a strong positive influence on BI (β = 0.492, p < 0.001). Strengthening farmers’ perceived control through training, credit access and infrastructural support can enhance entrepreneurial intentions and ensure their translation into sustainable agribusiness behaviour.