Reports from studies conducted in several countries indicate a high incidence of bacterial contamination of donor blood. The prevalence of bacterial contamination of blood and its products in Ghana is not known. This study was conducted to determine the prevalence of bacterial contamination of blood and its products at the three major blood transfusion centers in the Greater Accra Region of Ghana. Stored whole blood and its products were cultured on different media, and isolates were identified using standard biochemical and bacteriological methods. The susceptibility of the isolates to selected antimicrobial agents was also determined by the disc diffusion method. The overall prevalence rate was 9% (28/303; whole blood, 13% [24/192]; plasma, 3% [2/79]; platelet, 9% [2/22]). The Gram-positive bacteria isolated were coagulase-negative Staphylococcus, S. aureus, and Bacillus spp., and the Gram-negative organisms were Yersinia enterocolitica, Citrobacter freundii, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. The Gram-positive bacteria were sensitive to cloxacillin, erythromycin, tetracycline, and gentamicin but resistant to penicillin, ampicillin, cefuroxime, and cotrimoxazole, while the Gram-negative bacteria were sensitive to amikacin and gentamicin but resistant to chloramphenicol, tetracycline, ampicillin, cefuroxime, cefotaxime (except Y. enterocolitica), and cotrimoxazole. Our results suggest that bacterial contamination of blood and its products is prevalent in Ghana.