Introduction: HIV/AIDS-related stigma remains an essential barrier to the formulated care delivery and improved quality of life of people living with HIV/AIDS in sub-Saharan Africa. Only a few studies have evaluated stigma and its determinants as concerns people living with HIV/AIDS in Nigeria. Methods: A cross-sectional design study recruited 386 people living with HIV/AIDS attending the government clinic, Federal Medical Centre, Abeokuta, Nigeria, for the assessment of stigma using Berger’s HIV stigma scale and United States Agency International Development-recommended indicators and questions on HIV-related stigma among people living with HIV/AIDS. Data were analyzed using SPSS 21. Results: Of the 386 people living with HIV/AIDS, 322 (83.4%) were females and 64 (16.6%) were males, and 96.9% had disclosed their HIV status. Overall, mean perceived stigma score was moderately high at 95.74 (standard deviation = ±16.04). Majority (77.2%) of the participants experienced moderately perceived stigma. Among the subscales, disclosure concerns contributed the most to stigma score at 68.9%. Enacted stigma in the last 12 months was documented in 35.8% (138). There was no association observed between age, gender, marital status and HIV-related stigma. However, low education was associated with higher negative self-image perception (31.83 ± 5.81 vs 29.76 ± 5.74, p < 0.001). Furthermore, higher perceived stigma score was associated with abandonment by spouses (p < 0.001), isolation from household members (p < 0.001) and social exclusion (p < 0.001). We demonstrated a correlation between the domains of enacted stigma and Berger HIV stigma scales except for the loss of resources. Conclusion: Perceived HIV-related stigma is moderately high among people living with HIV/AIDS. Low education, disclosure concerns, spousal or household abandonment and social exclusion are the significant contributors. HIV-related stigma preventive interventions at different levels of care are advocated.