MA (Psychology) / Department of Psychology / Background: Given that there is 57.7 million HIV-diagnosed people living in South Africa and the government has established the largest public antiretroviral programme in the whole world but only 53% are adhering. Adherence remains a challenge, due to presence of mental health issues among HIV diagnosed. Aim: The aim of this study was to investigate adherence to antiretroviral therapy and mental health of HIV-diagnosed patients in Vhembe District, Limpopo Province. Methods: This was a mixed method study using a combination of quantitative and qualitative research approaches. In the quantitative approach, triangulation was utilised in the form of a questionnaire and patients records. Simple random sampling was used to select 134, descriptive analysis using SPSS version 25. For the qualitative approach, a phenomenological research designs was considered and convenience sampling was used to select fifteen participants (15). Data was collected using semi-structured interview; responses were analysed using a computer-aided program called, ATLAS ti. Results: The self-report of adherence was 94.8 %, objectively 39.6% of CD4 count <200c/mm3 at baseline and 34.3% CD4 count after six months was found. 16.5% of females and 2% of males defaulted treatment and 14.9% of missed medical appointments 1-6 times. This study also revealed the mental health issues that HIV-diagnosed patients are struggling with after the diagnosis include the stages of grief, stress, depression, anxiety, mistrust, shame, stigma and discrimination. Recommendation: Effective strategies need to be enhanced and tailor made in effort to encourage patients to take ART diligently. The healthcare providers, community members and the government should be made aware of mental health issues. / NRF