PurposeThe constant population growth and inappropriate consumption patterns have led to abnormal use of the earth's capacities, destruction of natural resources, enormous spread of diseases, and increased waste materials. Thus, these issues should be highlighted to avoid serious problems for the earth. Accordingly, this study examines the effect of environmental knowledge (EK), environmental responsibility (ER), and environmental concern (EC) on sustainable consumption behavior (SCB), with the mediating role of customer attitude (CA).Design/methodology/approachThe present applied study is descriptive-correlational. The statistical population includes customers of Hyperstar stores located in Tehran. Overall, a sample size of 384 people was selected based on Cochran's formula. The data were collected using standard questionnaires and analyzed using structural equation modeling and Smart PLS version 3 software.FindingsThe fit of the proposed model was confirmed at measurement, structural, and general levels. Thus, it indicates that the structural model has an acceptable fit. Furthermore, the findings emphasize that ER and EC have a positive effect on CA, and ER and EC have a positive impact on SCB. ER and EC have a positive effect on SCB through the mediation of CA, while EK does not have any significant effect on SCB but EK has an effect on SCB through the mediation of CA.Originality/valueGiven the growth of environmental destruction, it is necessary to consider the change of CA toward buying sustainable products. Therefore, this study pays attention to the mediating role of attitude and examines the effects of EK, EC, and ER that cause SCB among customers of Hyperstars.