Green purchase behaviour is receiving a growing attention in the academic community, as understanding it is crucial for the growing number of companies developing and marketing green products. In order to provide a broader and novel picture of the phenomenon, this study extends the widely used Theory of Planned Behaviour (TPB) model in several ways, through a large survey of Italian consumers. First, three dimensions of green purchase behaviour are considered, namely, the willingness to pay a premium price, the green purchase frequency and the green purchase satisfaction. Second, several antecedents are considered simultaneously. Third, new (consumer creativity) or so far marginally studied (materialism and green practices) antecedents are included. Fourth, the mediating roles of green purchase satisfaction and willingness to pay a premium price in the link between the considered antecedents and the frequency of green purchase are investigated. Results show that the three dimensions of green purchase behaviour have different antecedents, so highlighting that green purchase behaviour is a multi‐faceted phenomenon that should not be studied as a single general concept. Personal norms and value for money emerged to be very relevant predictors. The significant effects of creativity, materialism and green practices provide evidence that extending the TPB model with these three antecedents is useful to more deeply understand green purchase behaviour. Green purchase satisfaction is the strongest predictor of purchase frequency and mediates the effects of personal norms and value for money.