Despite advances in modern blood banking procedures and all precau­tions taken, a small but significant number ot blood transfusions are still complicated by various kinds of ad­verse reactions, some patients with transfusion dependent disease be­comes difficult to transfuse due to multiple blood group antibodies, also the haemolytic reactions are serious and potentially harmful to patients having these antibodies {Hu.h and Lichtiger, 1987). Brantley and Ramsey (1988), re­corded red cell a Ho antibodies in 9.5% and multiple antibodies in 3.7% in pol-ytransfused patients. While Walker and Hartrick (1989) estimated alloan-tibody frequencies in patients follow­ing blood transfusion, they revealed a gradual decline in the frequencies of anti-D and anti-CD, whereas anti-K, anti-E and anti-JKa showed increases in relative and absolute frequencies, these problems may pose additional risks to the transfused recipient. For this reason we planned this work to find the incidence of alloanti-body Production in patients, received multiple blood transfusions during per­iod (1986-1990).