PurposeAdopting the theory of planned behavior, this study attempts to investigate how subjective norms in the supply chain influence a firm's green innovation and how such influences are contingent upon the firm's internal and external factors (i.e. flexibility orientation and environmental dynamism). Two types of subjective norms are examined, i.e. injunctive norms (what supply chain partners say) and descriptive norms (what supply chain partners do).Design/methodology/approachUsing survey data of 178 Chinese small and medium-sized manufacturers, we employ hierarchical linear regression to test the proposed hypotheses.FindingsOur results indicate that both injunctive and descriptive norms are instrumental in stimulating firms to take actions on green innovation. Moreover, the flexibility orientation of a firm can strengthen the effect of descriptive norms. It is also observed that environmental dynamism weakens the efficacy of injunctive norms but strengthens that of descriptive norms on green innovation.Originality/valueThis study is among the first to apply the theory of planned behavior to explain the microfoundations of focal firm's green innovation and distinguish two types of subjective norms in the supply chain. In addition, it extends the theory of planned behavior by revealing internal and external contingent factors (i.e. flexibility orientation and environmental dynamism) of the relationship between subjective norms and firm behaviors.