The identification of carriers for the hemophilia A gene was carried out in 20 families of hemophilia A patients. The detection of the carriers was performed on the basis of the study of restriction length fragment polymorphism (RLFPs) for the enzymes BclI and HindIII. The procedures for the determination of RLFPs included the amplification of fragment of the factor VIII gene by the polymerase chain reaction (PCR) followed by digestion with the appropriate enzyme. We studied 84 relatives of the patients with hemophilia A and was possible to detect carriers in 76% of the families. The results presented here indicate that is possible to identify carriers for hemophilia A in most of the families of patients from the Brazilian population employing a limited number of RFLPs.