Encouraging individuals' environmentally responsible behaviours (ERBs) is becoming increasingly important for tourism destination management. This study was designed to investigate the formation of the ERBs of tourists from a broken windows theory perspective. Results from a sample of 307 tourists highlighted the antecedent role of tourists' perceived environment quality among the relationships between the variables of theory of planned behaviour (TPB), moral obligation, and the intention to engage in ERBs. The results of multiple mediation analysis revealed that the TPB variables and moral obligation act as full mediators in the effect of perceived environment quality on ERBs intention. The relative importance of the TPB variables and moral obligation in predicting the intention to engage in ERBs were also compared in this study.