Background: Mental health and HIV counselling has received global public health interest because of its impact on HIV burden. People living with HIV have a right to a quality of life which enables them to participate in individual, family and community development issues. With the advent of HIV in Zimbabwe, it became apparent that a full range of clients and patients seen at health facilities could benefit from HIV counselling and testing. Nurses and doctors, overwhelmed with patients did not have enough time to cover all aspects of prevention, treatment, care and support to patients and their families especially in the context of HIV counselling and testing. In 2005 after a wide consultation with stakeholders, the Ministry of Health and Child Care (MOHCC) introduced the primary counsellor (PC) programme (lay counsellor equivalent) to enhance the counselling capacity for HIV testing and counselling for prevention, treatment, care and support. While periodic reviews of the HIV and AIDS programme have been done to monitor implementation, no formal evaluation of the primary counsellor program had been done to assess its effectiveness hence the need to conduct this evaluation study. The purpose of the study was to assess the efficacy of primary counsellor programme in delivering HIV counselling in Zimbabwe, regarding addressing HIV and mental health needs for clients accessing HIV prevention, treatment, care and support services so that they could make informed decisions about their personal, social, and emotional health. Methods: Methodological triangulation of data involved collection and analysis of qualitative and quantitative data through structured and semi structured interviews from 395 primary counsellors, 395 key informants (health workers) and 395 HIV positive clients who had accessed primary counselling services. Respondent were selected through stratified random sampling from central, provincial, district, mission and rural hospitals as well as primary health facilities of Zimbabwe from January to April 2018. Results: the majority of the interviewed respondents were women: key informants 277(70%), Primary counsellors 267 (67.6%) and clients 264 (67.0%). Education requirement for primary counsellors’ selection and recruitment was five O level passes, the study revealed that, 30 (7.6%) had advanced level and 63 (16.0%) higher level, academic degrees, showing potential for further development. While both gender of clients accessing primary counselling were affected, women (182; 46.1%) and young people of the 15- 24 age group (283; 71.7%) seemed to be mostly affected and normally presenting with mental health signs and symptoms. While reduction of HIV transmission was attained at 97%, it was noted that 155 (39%) of the clients reported that they had managed to adapt to lifestyle changes. Clients’ findings also revealed that 39% of clients had been stigmatised; showing no difference of occurrence by gender. There were three distinct areas of linkages and referral which were medical v care (93.9%), nutrition services (73%) and support groups (69.1%). In the qualitative findings, clients mentioned social and physical challenges they faced that caused them not to adhere to medication. After enhanced adherence counselling and psychosocial support, most of the clients had undetectable viral loads. Conclusion: In this first study for Zimbabwe, the primary counsellor programme was effective in delivering HIV and mental health counselling services. There is need to strengthen services to include non-communicable diseases and other medical conditions beyond the HIV emergency span. The study proposed a psychological services model for the Ministry of Health and Child Care from central to primary health facility level; national level policy issues and key areas for service provision