The current study investigates farmers’ behavioral intentions toward adopting biopesticides in India, integrating the theory of planned behavior and health belief model. The models were further expanded by the inclusion of a control variable, Government Initiatives. A total of 468 responses from four districts (Patna, Bhagalpur, Purnea, and Saharsa) in Bihar were collected by face-to-face surveys and analyzed using the SmartPLS 4 software by structural equation modeling to assess the correlation between the constructs. The hypothesis testing employs a bootstrapping method with 5,000 iterations. The present study demonstrated a strong positive correlation between all variables derived in the integrated model. Perceived severity strongly influenced farmers’ attitudes toward adopting the use of biopesticide. Furthermore, subjective norms and government initiatives emerged as the most important factors influencing farmers’ intentions toward adopting biopesticide. Premium price, low effectiveness, and reduced crop productivity emerged as significant challenges to the adoption of biopesticides. To address these challenges, this study suggests providing farmers with affordable solutions and resources in collaboration with the government. The proposed study provides significant information and facilitates the understanding of farmers’ inclinations to utilize biopesticides. The government and policymakers can address key barriers to the adoption of biopesticides—such as income inequality—by offering subsidies for organic food production, developing an efficient and dedicated supply chain for input and output organic produce, and formulating strategies to optimize the use of biopesticides in order to promote long-term sustainability.