Purpose - The present study sought to obtain a better understanding of the determinants that influence the adherence to individual walking groups. Design/methodology/approach - The study took place as part of the "Just Walk It" (JWI) programme of the Australian National Heart Foundation. The research model incorporated social environmental, physical environmental, cognitive and socio-demographic factors. Participants (n=284; response rate 49.6 per cent) of the JWI programmme completed a survey, which measured environmental, cognitive and socio-demographic factors. Exercise adherence was monitored over a period of 12 months. To identify the potential predictors bivariate correlation analyses and linear regression analyses were performed. Findings - Social cohesion was identified as the sole predictor of adherence to walking groups, while cohesion was further associated with positive attitudes regarding physical activity. Furthermore, participants who perceived their neighbourhood as positive in terms of safety and friendliness were more likely to have a positive attitude toward exercising. Originality/value - The present study indicates the importance of acknowledging the social environment in designing walking group interventions. This paper offers useful information for individuals designing interventions aimed at increasing physical activity.