The aim of this study was to determine the prevalence of kidney disease in patients newly diagnosed as HIV-positive in Brazzaville and to identify the associated risk factors. Descriptive and analytical study of patients diagnosed with HIV infection at the Ambulatory Treatment Center in Brazzaville, Republic of Congo, from January 1, 2009, through December 31, 2010. Estimated glomerular filtration rate (eGFR) was assessed with the Modification of Diet in Renal Disease equation (MDRD-GFR), and kidney disease was defined by an eGFR less than 60 mL/min/1.73 m(2). We conducted a univariate and then a multivariate logistic regression analysis to determine the factors associated with kidney disease in this population. The study included 562 patients newly identified as HIV-infected, 66.13% of whom were women. Their median age was 38.84 years interquartile range (IQR): 33.18-46.23) and their median body mass index (BMI) 20.31 kg/m(2) (IQR: 17.97-22.89). Their median CD4 count was 192 cells/mm(3) (IQR: 81-350), and 70.8% were at WHO stage III/IV. Finally, the median MDRD-GFR was 95.59 (IQR: 78.76-114.92) mL/min/1.73 m(2) and 8.5% had a GFR less than 60 mL/min/1.73 m(2), that is, moderate impairment of kidney function. The only factor associated with kidney disease in the multivariate analysis was a BMI less than 18.5 kg/m(2) (adjusted odds ratio: 2.54, 95% confidence interval: 1.25-5.15, p = 0.01). The prevalence of kidney disease in patients newly diagnosed with HIV in Brazzaville is relatively high. The only factor associated with it in the multivariate analysis was a BMI less than 18.5 kg/m(2).