1. A case of congenital afibrinogenemia of a Sinhalese boy of 22 years is reported.
2. The main features of the reported cases are reviewed.
3. The principal features of this case are total absence of fibrinogen in the blood, complete non-coagulability of blood, history of several episodes of hemorrhage dating from infancy, low erythrocyte sedimentation rate, cosanguinity of the parents and the occurrence of spontaneous hemoperitoneum from which he recovered after operation.
4. Treatment consists of blood or fibrinogen transfusion.