Purpose: This study aims to provide one of the first research works that, using the constructs of the theory of planned behaviour (TPB), analysed the levels of purchase intention of organic products. Design/methodology/approach: The study was quantitative with a correlational scope and a cross-sectional design. The study population consisted of 566 university millennials from Ecuador. The results were processed through the exploratory factor analysis (EFA), the confirmatory factor analysis (CFA) and the structural equation modelling (SEM). Findings: The subjective attitudes and norms influence intentions to buy organic products. However, price mediated by perceived behavioural control reduces purchase intentions, while product availability does not. Originality/value: This study is one of the first research works, based on the constructs of the TPB which was carried out to know if the attitudes and subjective norms of Ecuadorian university millennials, are related to their purchase intentions for organic products.