Despite huge environmental, economic, health, and social costs of pesticides, evidence revealed that farmers in developing countries would continue to use pesticides. The root of the problem appears to be related to the way of farmers’ decision making. As such, it is crucial for policymakers to understand how farmers think and behave with regard to these inputs. Therefore, the aim of this research was to accrue empirical evidence about greenhouse owners’ attitudes and intention toward avoiding using pesticides in Bandar Abbas District using the Theory of Planned Behaviour (TPB). TPB was tested using a survey to understand greenhouse owners’ attitude and intention. The study sample consisted of 110 greenhouse owners selected through a random sampling method. Data were collected with a structured questionnaire to assess the central variables of the theory. The questionnaire’s internal reliability and validity were confirmed by a panel of experts. Results indicated that the greenhouse owners’ moral norm was the main predictor of their intention to avoid pesticide application followed by the variables of self-identity and attitude, respectively. Furthermore, adding moral norm and self-identity as additional constructs to the theory significantly improved the explanatory power of the standard model.