Our aim was to study the prevalence of the human cytomegalovirus (HCMV) among blood donors and AIDS patients and to examine a clinical correlation between AIDS and HCMV seroprevalence in Bamako (Mali, West Africa). We have used Elisa kits for detecting HIV and HCMV specific antibodies. The HCMV seroprevalence was 89% among AIDS patients, 71% among HIV-infected blood donors and 58% among HIV-uninfected blood donors. The HCMV seroprevalence rate was higher among AIDS patients than among HIV-uninfected blood donors (p=0.0000007) and than among HIV-infected blood donors (p=0.00146). There was no significant difference between the HCMV seroprevalence among HIV-infected blood donors and among HIV-uninfected blood donors (p=0.0547). There was no relationship between HCMV seroprevalence and sex or age among AIDS patients and blood donors. There was a significant difference on pneumonia among HCMV-infected AIDS patients and among HCMV-uninfected AIDS patients (40% versus 0%; p=0.005). Buccal and phaiyngal candidosis, dermatosis, Kaposi's sarcoma and nervous system diseases had the same frequency among HCMV-infected and HCMV-uninfected AIDS patients.