OBJECTIVE: To review the experience of implementing a workplace HIV care programme in South Africa and describe treatment outcomes in sequential cohorts of individuals starting antiretroviral therapy (ART). DESIGN: A review of an industrial HIV care and treatment programme. Between October 2002 and December 2005, 2262 patients enrolled in the HIV care programme. RESULTS: CD4 cell counts increased by a median of 90, 113 and 164 cells/microl by 6, 12 and 24 months on treatment, respectively. The viral load was suppressed below 400 copies/ml in 75, 72 and 72% of patients at 6, 12 and 24 months, respectively, at an average cost of US$1654, 3567 and 7883 per patient virally suppressed, respectively. Treatment outcomes in sequential cohorts of patients were consistent over time. A total of 93.6% of patients at 14,752 clinic visits reported missing no tablets over the previous 3 days. Almost half the patients (46.8%) experienced one or more adverse events, although most were mild (78.7%). By the end of December 2005, 30% of patients were no longer on ART, mostly because of defaulted or stopped treatment (12.8%), termination of employment (8.2%), or death (4.9%). CONCLUSION: This large workplace programme achieved virological results among individuals retained in the programme comparable to those reported for developed countries; more work is needed to improve retention. Monitoring treatment outcomes in sequential cohorts is a useful way of monitoring programme performance. As the programme has matured, the costs of programme implementation have reduced. Counselling is a central component of an ART programme. Challenges in implementing a workplace ART programme are similar to the challenges of public-sector programmes.