Introduction: We set out to assess the distribution of HIV drug resistance mutations and their risk factors in patients failing 2nd line ART and to determine treatment outcomes among patients receiving 3rd line ART in Zimbabwe. Methods: This work was done in collaboration with the Zimbabwe Ministry of Health through the AIDS and TB program. Routinely collected program data was analysed and reported. Results: The following manuscripts were published in peer reviewed journals: 1. HIV-1 Drug Resistance and Third-Line Therapy Outcomes in Patients Failing Second-Line Therapy in Zimbabwe 2. Zimbabwe's National Third-Line Antiretroviral Therapy Program: Cohort Description and Treatment Outcomes 3. A case report of untreatable HIV infection in Harare, Zimbabwe Conclusion: Our findings demonstrate that poor adherence is the major cause of second-line ART failure. Access to HIV genotyping in Zimbabwe is low and may be a barrier to effective diagnosis of second-line ART failure and inappropriate switches to third-line ART.