This thesis investigated whether a novel interactive website covering emotionregulation via music-listening helped smokers to quit, over and above best-practice treatment provided by Queensland Quitline. Utilising a randomised-controlled mixed design, it was predicted that improvements to quitting likelihood for participants in the Music condition would be greater than for those in a Control condition whose interactive website contained generic quitting strategies already covered by Quitline’s treatment. Control participants in turn would have greater quitting likelihood improvements than treatment-as-usual participants, whose website was a static list of quit support services. Furthermore, changes in other quitting outcomes would be partially mediated by changes in emotion regulation abilities. Fifty-five smokers commencing treatment completed an online questionnaire of factors related to smoking cessation, before being randomly assigned to one of the three condition websites. The Music and Control websites each contained six videos and six activities based on them. Six weeks later, participants completed a final questionnaire to assess changes in quitting likelihood, including: smoking status; craving strength; self-efficacy; and emotion regulation without smoking. Results suggested that participants in the Music and Control conditions had greater reductions in craving strength and improvements in emotion regulation than treatment-as-usual. Control participants also displayed greater self-efficacy than the other groups. Partially supporting hypotheses, findings indicated the theoretical link between emotion regulation, self-efficacy, and smoking, and the suitability of emotion-regulatory interventions for cessation. Further, they connoted the potential of music-listening as a smoking cessation strategy. Explanations, theoretical, and practical implications are discussed, as well as future directions that would validate and build on the interpretation of results for this study.