A cross-sectional survey was conducted to determine the risk factors associated with intestinal parasitosis in HIV/AIDS patients receiving antiretroviral treatment. Socio-demographic information was collected and faecal samples were analysed from randomly selected 384 patients under antiretroviral treatment. Data on CD4+ T-cell counts and World Health Organization clinical staging were obtained from the medical records at the hospital. The overall prevalence of intestinal parasitosis was 65% (95% confidence interval: 51% to 61%). No opportunistic intestinal parasites and Schistosoma haematobium eggs were detected. Unavailability of latrine and lack of hand washing with soap were associated with Entamoeba histolytica/dispar (adjusted odds ratio, 2.75; 95% confidence interval: 1.77 to 4.27 and adjusted odds ratio, 2.67: 95% confidence interval: 1.60 to 4.44, respectively) and Giardia lamblia (adjusted odds ratio, 2.08; 95% confidence interval: 1.08 to 3.99 and adjusted odds ratio, 2.46; 95% confidence interval: 1.06 to 5.75, respectively) infections. Intestinal parasitosis was significantly associated CD4 cell count (p = 0.002). In contrast, intestinal parasitic infections were not associated (p > 0.05) with the World Health Organization disease staging. In summary, poor personal hygiene and sanitation practice contributed to the high prevalence of intestinal parasitosis. Routine diagnosis for intestinal parasitic infections should be performed in patients attending antiretroviral treatment clinic.