PurposeThe study investigates the role of locus of control and motivation in predicting green buyer behaviour using social cognitive theory. The study also examines the mediating role of motivation and the moderating role of health consciousness in the relationship between motivation and green consumer behaviour.Design/methodology/approachTo test the postulated relationships in the study, responses were collected from 410 customers. The study tested validity through confirmatory factor analysis and examined various hypotheses through Process Macros.FindingsThe analysis revealed that the locus of control of the buyer increases green buyer behaviour. The study established a positive relationship between internal and external locus of control and intrinsic and extrinsic motivation, impacting green buyer behaviour. The study also identified evidence supporting the mediating role of intrinsic and the extrinsic motivation and the moderating influence of health consciousness.Practical implicationsThe study expands upon current theory by illustrating the association between intrinsic and extrinsic motivation and customers' green purchasing behaviour. It enhances existing literature by identifying health consciousness as a personal factor influencing the connection between motivation and eco-friendly purchasing, urging marketers and policymakers to promote green buying.Originality/valueTo the best of the authors’ knowledge, no prior studies have examined the effect of internal and external locus of control on green buyer behaviour. Through identifying the mediating mechanism and health consciousness as a personal factor, the study enhances both theoretical understanding and practical applications.