BACKGROUND Despite the higher prevalence of psychiatric disorders among people living with HIV/AIDS (PLWHA) than the general population and the possibility that the occurrence of these disorders can be influenced by family support provided to this group of people, only little attention is giving to mental health and the family influence in the routine management of HIV infection. In view of this and other related issues, this study was set out to determine how common are psychiatric disorders and their relationship with family support among PLWHA attending highly active antiretroviral therapy (HAART) clinic of UITH, Ilorin Kwara State. AIM AND OBJECTIVES The study aimed to determine the relationship between family support and psychiatric comorbidities among adult PLWHA attending HAART clinic at UITH, Ilorin, in order to provide additional information that could guide caregivers and policy makers in effective psychosocial interventions targeting PLWHA. It also determined the prevalence of common psychiatric disorders (CPD) [depression, anxiety disorder (AD) and alcohol use disorder (AUD)], the level of family support, the association between family support and CPD, as well as the relationship between CPD and some respondents’ clinical parameters like CD4 counts, body mass index (BMI) and WHO HIV clinical staging. MATERIALS AND METHOD It was a hospital based descriptive cross-sectional study conducted among 363 respondents within a period of three months using semi-structured questionnaires. Mini International Neuropsychiatric Interview (M.I.N.I) was used to assess the prevalence of CPD while Perceived Social Support – Family (PSS-Fa) was used to asses level of family support, anthropometric xx measurements and laboratory test for CD4 counts were also done. Data was analyzed using the Statistical Package for Social Sciences version 21. Chi-square tests were performed to compare associations between categorical variables and probability (p) value of less than or equal to 0.05 was taken as statistically significant. RESULTS The majority of the respondents were between 31-40 years (35.3%) while only 30 (8.2%) were 30 years and below. A larger proportion of the respondents were female 262 (72.2%) while males were almost one third 101 (27.8%). The overall prevalence of depression was 24.5%, AD was 16.8% while AUD was 0.6%. Family support was strong among majority of respondents (93.7%). There were significant associations between CPD (depression and AD) and family support among the respondents with p-values 0.001 and < 0.001 respectively. AD was found to be significantly associated with CD4 counts and WHO HIV disease staging (p values 0.008 and < 0.001). AUD also had significant association with WHO HIV disease staging (p = 0.001). Multiple logistic regression analysis established that family support and CD4 count ≥ 500 cell/ul were better predictors of CPD with odd ratio (4.321 and 4.301) respectively.