Objective: This retrospective study was conducted using data from the 2005 to 2012 archives at the Laboratory of Bacteriology Serology and Hygiene of Ibn Sina University Hospital Center in Rabat, Morocco. Its aim is to determine the prevalence of bacterial contamination of platelet concentrates produced by the Regional Center for Blood Transfusion of Rabat, after the implementation of the bacterial quality control of the platelet concentrates. Methods: A total of 3898 platelet concentrates, obtained after disinfection of the sampling site and diversion of the first milliliters of the blood donation, were cultured to study bacterial contamination between 2005 and 2012. The obtained bacterial colonies are tested by Gram staining and orientation tests such as: catalase, coagulase, oxidase, as well as the biochemical gallery for identification. This retrospective study was conducted over a period of six months using data from the archives of the Laboratory of Bacteriology Serology and Hygiene of Ibn Sina University Hospital Center in Rabat, Morocco. Results: This retrospective study concluded that the prevalence of bacterial contamination in platelet concentrates is 0.44 %. It also showed the presence of the following bacteria species: coagulase-negative Staphylococcus species and Bacillus sp each at 29.41%, Staphylococcus aureus, Streptocoque, E.coli and Enterobacter each were found at 5.9%. Other bacilli’s grams negative were present at 17.65 %. Conclusion: Even though, the prevalence of bacterial blood contamination found in this study was low, blood transfusion in Morocco has a long way to go before reaching the standards set and commonly accepted in developed countries.