Aim of the study.-In this study, we tried to estimate the prevalence of weak D in Moroccan population, based on the serological techniques. Materials and methods.-This study was conducted in the National Center of Transfusion sanguine of Rabat, from 01 January 2011 to 30 June 2011. During this period, a total of 23,098 donors were typed for rhesus D antigen at PK 7300 Olympus. Those who tested negative for rhesus D antigen were further subjected to weak D testing. Results.-In this study, 0.9% of the donors were rhesus negative and the weak D phenotype was detected in about 0.4%. Conclusion.-The finding of 0.4% prevalence of weak D phenotype among donors in this study is concordant to those found in Caucasians (0.2% to 1%). (c) 2012 Elsevier Masson SAS. All rights reserved.