Human herpesvirus 8 (HHV-8) infections, have been associated with Kaposi’s sarcoma (KS). KS is listed as one of the AIDS defining illnesses. Studies indicating the role of this virus in AIDS associated KS in Africa are few. Aims and objectives of study The aim of this study was to determine the prevalence of KS in patients with HIV infection, describe its clinical-epidemiological characteristics and also determine the presence of HHV-8 in AIDS-KS. Methodology Confirmed HIV positive patients who presented to the clinics and wards of the University College Hospital (UCH) within the period of October 2008 to September 2009, were examined for KS. The pattern of presentation was described and the diagnosis of AIDS-KS confirmed histologically. To document the possible association of risk factors, a control group of HIV positive patients without KS, age and sex matched was recruited. Their clinical, immunological and virological characteristics were compared. The presence of HHV-8 infection was detected immunohistochemically using the HHV8 LANA1 (orf 73, clone13B10) antibody. Sixteen tissue sections of non-KS lesions (including 7 from HIV-positive patients) were used as negative control. A positive stain was observed in the nuclei of KS cells (spindle and endothelial) and further categorized in percentages (10% to 100%) while intensity of stain was classified as weak, moderate and severe. Results were analyzed using SPSS package version 16. Results Thirteen patients with AIDS-KS were recruited during the study period. The prevalence of AIDS-KS in Ibadan is 0.5% and the male: female ratio was 1.2:1. There was no statistical difference between the case and control groups’ number of lifetime sexual partners (P=0.61), history of STD (p=0.39), CD4 count (p=0.70) and HIV-1 viral load (p=0.20). All the patients presented with multiple sites of involvement. Most of the patients (74%) presented at the plaque and nodular stage(s) of the disease. All the AIDS-KS tissue sections indicated a positive stain for the HHV-8 antigen (p=0.001) while the non-KS tissue sections were negative. The difference in the percentage cell with positive stain and the intensity of stain was not significantly affected by the CD4 count and viral load of the patient (P=0.30 and 0.94 respectively). Conclusion The prevalence of AIDS-KS in Ibadan is slightly lower than previous reports in other parts of the country. Presently the duration before diagnosis is unacceptably long. AIDS-KS occurs significantly in females. HHV-8 is present in all lesions of KS and immunohistochemistry to detect the viral antigen is a diagnostic tool for diagnosis of KS