Purpose This paper aims to examine the influence of environmental concerns and consumers’ knowledge of green brands on their purchasing decisions of green products, utilising green trust as a mediator. Design/methodology/approach Responses from 383 Indian consumers were collected, which was analysed using descriptive and inferential statistics. The causal relationships between latent variables and mediating effect of green trust were investigated by performing Structural Equation modelling. Findings Green trust served as a crucial factor in mediating the relationship between environmental concern and green purchase decision. Trust in eco-friendly products significantly influenced the consumers’ decisions to make green purchases. The study further validated that environmental concern significantly influences individuals’ decisions to make green purchases. Research limitations/implications The study employed a cross-sectional research design to elucidate the relationship among the factors. However, a longitudinal research design is recommended for further study to ascertain the actual purchase decision and evaluate the reliability of the results. Practical implications Marketers can use the study findings to understand consumer knowledge better and trust in green and sustainable products. The proposed model will support marketers and policymakers in developing appropriate marketing strategies as well as facilitate educating consumers about the nuances of green products and the habit of buying eco-friendly products. Originality/value Study’s novel contribution is mediation between environmental concern and green purchase decision through green trust.