Background Mental health (MH) remains a neglected priority in many low and middle-income countries compounded by huge inequity in the distribution of skilled human resources for MH services and inadequate data. Inadequate knowledge about MH and negative attitudes towards people with MH disorders is widespread among the general public. Methods This was a descriptive cross-sectional survey that utilised mixed methods for data collection. A total of 535 community members and 109 healthcare workers (HCWs) were targeted for the study. Simple random sampling was used to select healthcare workers in selected health facilities. Data were collected using household surveys, Key Informant Interviews (KIIS) with facility in-charges; Focus Group Discussions (FGD) with community members particularly community Health Volunteers (CHVs) and youth; and In-depth Interviews(IDI) with community gate keepers. Data analysis included simple univariate frequencies of questions chosen to reflect the key concepts on mental health. Descriptive statistics were used to determine frequencies and percentages for the different variables under study. For qualitative data, thematic analysis was applied to generate themes through deductive and inductive methods. Triangulation of qualitative and quantitative data was conducted. Results Approximately 39.1% of respondents reported to have had a family member with mental illness. 68% of HCWs reported to have diagnosed a patient with mental illness. 64% of respondents cited causes of mental disorders as witchcraft; generational curses in some families; genetic factors; drug and substance abuse social and economic/financial pressures and injuries from accidents. 93.3% of HCWs reported to have referred patients to a MH facility. Only 29.4% of the HCWs reported having counselling services for MH patients. Majority (90.8% HCWs and 62.3% community members) reported that it is convenient for patients with MH needs to access the health care facilities. MH services are mainly offered at the Teaching and Referral Hospital (81.7% HCWs and 53.8% community members). Majority of HCWs (89.9%) reported that MH services were affordable contrary to community members (44.4%). HCWs reported that drugs were given for free while community members reported stock-outs leading to purchase of MH drugs from pharmacies. Majority (96.4% HCWs and 62.5% community members) reported that MH patients are treated with respect in the facilities. Community members also seek MH services from religious leaders and traditional healers who are approached for cleansing. Additionally, some families did not seek any kind of help for their relatives with mental health illness and needs, with some even detaining them. Conclusion This study adds to the global knowledge on MH among healthcare workers and community members at service delivery level from a developing country. There is evidence of high burden of MH with very few facilities offering MH services. The existence of myths and misconceptions on causes of MH is evident.  Disparities in perception of HCWs and Community members in MH on availability, affordability of  services and access to drugs is evident. There is need to build the capacity of health care workers and sensitize community members as well as strengthen health systems to tackle MH.