: South Africa's government has made significant improvements in expanding access to antiretroviral (ARV) treatment. A rate of adherence of 95% to 100% is necessary to achieve the intended outcomes of antiretroviral treatment. However, antiretroviral treatment adherence remains a significant challenge at Helen Joseph Hospital, where an adherence rate of 51% to 59% has been reported.: The goal of this study was to examine the factors associated with ARV therapy non-adherence among HIV patients at Helen Joseph Hospital.: The study used a case-control design. There were 32 570 eligible patients for this study and 322 were selected from the overall population. Epi Info™ 7.2 was used to calculate the sample size. A total of 322 questionnaires were administered to participants during their clinic visits. The Aids Clinical Trial Group (ACTG) Questionnaire was used to measure and describe factors associated with ART treatment defaulting. Epi Info™ 7.2 was used to calculate crude odds ratios and SPSS version 26 was used to conduct multivariate logistic regression to compute adjusted odds ratios at 95% confidence intervals and -values.: In total, there were 322 (100%) study participants, of which 51% ( = 165) were non-adherent to ARV therapy and 49% ( = 157) were adherent. Participants' ranged between 19 and 58 years old, with a mean age of 34 years old and a standard deviation of 8.03 years. Treatment non-adherence was associated with long waiting times at Helen Joseph's Themba Lethu Clinic after adjusting for gender, age, educational level and employment status. The adjusted odds ratio was 4.78, 95% CI 1.12-20.42, and = 0.04.: The study explored factors associated with ARV treatment defaults at Helen Joseph hospital. The long waiting times at the hospital were strongly associated with non-adherence to ARV treatment. A reduction in clinic waiting times will result in improved adherence to ARV treatment. To reduce long waiting times, the study recommends a multi-month medication dispensing programme and differentiation of HIV care. We recommend that future research include patients and clinic managers (as well as other key players) in the development of solutions to reduce waiting times.: Helen Joseph Hospital did not view long waiting times as a factor that would cause a patient to default on their ARV treatment in the past. Helen Joseph Hospital's management team was influenced by the study results. To achieve an adherence rate of 95% to 100%, the hospital is reducing waiting times.