This study aimed at assessing the sustainability of the Rea Vaya Bus Rapid Transit (BRT) system through assessing how the seven elements of service quality affects the commuters’ satisfaction with the service render by the Rea Vaya system, and its impact on its sustainability. The rationale for this assessment was to determine whether the system will continue to operate at a low cost for its customers, offer a high service quality that retain commuters and thus, sustain Rea Vaya’s profitability in the future. A quantitative research method was used for this study, the method allows numerical data collection and enables the study to analyse data. The use of a quantitative data collection method helped in answering the primary and secondary objectives. A questionnaires was used as a means of collecting data by handed out to BRT users at selected bus stations on specific routes in Johannesburg. The target population consisted of all users of the Rea Vaya BRT system, Rea Vaya transports an average of 16 000 commuters every day. The sampling unit can be found at five of the fifty-eight Rea Vaya stations currently operational.