Paid sex is associated with HIV and other sexually transmitted infections, which are highly prevalent in Sub-Saharan Africa (SSA). However, few data exist on this sexual practice among the general population in SSA, including the Democratic Republic of the Congo, where data on paid sex mainly comes from sex workers. In the DRC, most HIV Voluntary Counseling and Testing (VCT) centers do not discuss paid sex as a risk factor. Thus, we aimed to analyze the prevalence of paid sex, its associated factors and association with HIV among women and men attending HIV VCT at a reference hospital in Kinshasa. From 2016 to 2018, the Observational Kinshasa AIDS Initiative cohort analyzed the impact of HIV VCT on changes in HIV knowledge, attitudes, and sexual behaviors at follow-up. Participants aged 15–69 years were HIV tested and interviewed at baseline and at 6- and 12-month follow-ups. At baseline, participants were asked about their history of “ever” having had exchanged sex for money. At both follow-ups, the frequency of this practice was referred to as “the previous 6 months.” Descriptive, bivariate, and multivariate logistic regression analyses were carried out to evaluate the prevalence of paid sex, its associated factors, and the association between paid sex and HIV. Statistical analyses were performed with Stata 15.1. Among 797 participants at baseline, 10% of those sexually experienced reported having ever had paid sex (18% men and 4% women, p < 0.001). At 6 and 12-month follow-ups, 5% and 2%, respectively. Paid sex was significantly and independently associated with being male (aOR = 2.7; 95% CI = 1.4–5.2), working or studying (aOR = 2.8; 95% CI = 1.5–5.0), daily newspaper reading (aOR = 4.4; 95% CI = 1.7–11.2); daily/weekly alcohol consumption (aOR = 3.3; 95% CI = 1.8–6.1), first sexual intercourse before age 15 years (aOR = 2.3; 95% CI = 1.1–5.0), multiple sexual partners (aOR = 4.1; 95% CI = 2.2–7.7), and extragenital sexual practices (aOR = 2.4; 95% CI = 1.3–4.4). A high religiosity (daily/weekly church attendance and praying) was inversely associated with paid sex (aOR = 0.1; 95% CI = 0.0–0.4). The high prevalence of paid sex among people attending HIV VCT in Kinshasa, associated with other sexual and consumption risk behaviors, highlights the need to include paid sex among the risk factors mentioned in HIV prevention counseling.