Background: The purpose of this study was to determine the cross-sectional association between some sociodemographic factors and antiretroviral therapy (ART), as well as the incidence and predictors of type 2 diabetes mellitus among Central Africans with human immunodeficiency virus (HIV) disease. Methods: This study had a cross-sectional design and was a prospective analysis of 102 patients with HIV disease (49 on ART versus 53 not on ART) in Kinshasa, Democratic Republic of Congo, between 2004 and 2008. A Cox regression model was used to assess for any relationship between type 2 diabetes and exposure to combination ART without protease inhibitors, after adjusting for known risk factors for type 2 diabetes, nadir CD4 and CD8 levels, viral load, marital status, and religion. Results: Unexpectedly elevated rates of smoking, excess alcohol intake, and ART-related total, abdominal, and peripheral obesity were observed in our study group of HIV patients. At the end of follow-up, five patients were diagnosed with type 2 diabetes (incidence rate 4.9%, 9.8 per 1000 person-years). Univariate risk factors for type 2 diabetes were male gender (relative risk [RR] 1.1, 95% confidence interval [CI] 1.01–1.4; P = 0.019), traditional religion versus new charismatic religion (RR 1.1, 95% CI 1.01–1.3; P = 0.046), exposure to ART (RR 1.1, 95% CI 1.002–1.3; P = 0.034), and single status (RR 6.2, 95% CI 1.5–15; P = 0.047). In multivariate analysis, strong significant independent predictors of type 2 diabetes were belonging to a traditional religion (HR 2.1, 95% CI 1.1–4.2; P = 0.036) and a relative increase in nadir CD4 cell count (beta coefficient 0.003; P < 0.0001). Conclusion: ART-related obesity and type 2 diabetes are becoming increasing problems in Central Africans with HIV disease. A relative increase in nadir CD4 count and traditional religion status appear to be the strongest independent predictors of type 2 diabetes.