Blood transfusion is a necessary therapeutic method in blood diseases treatment. Blood transfusion gets only high result when the patients are transfused safely and effectively. Study on rate and characteristic of irregular antibodies in the blood diseases patients, special in the patients who were transfused many times will help the patients are transfused matched blood units and more safely. Objectives: Study on rate and characteristic of irregular antibodies in blood diseases patients in National institute of hematology and blood transfusion (NIHBT) from 2009 to 2012. Materials: 2.598 blood diseases patients whose age from 1 to 92 were treated in NIHBT from December 2009 to March 2012. Methods: Using gelcard method on Hemos SPII automachine system with screening cell and panel cell which were made in NIHBT to detect patients' irregular antibodies. Results: the authors found out 147 patients have irregular antibodies among 2.598 patients (made up 5,7 percent). The highest irregular antibodies rate was found in Rh blood group system: 55,9 percent (Anti-E: 35,3 percent
anti-c: 18,5 percent
anti-C: 2,1 percent), anti-Mi of MNS blood group system made up 28,6 percent, Kidd's antibodies, Duffy's antibodies, P's antibodies and Lewis's antibodies made up lower rate. Irregular antibody rate in woman patients is higher than man patients (man: 4,2 percent, woman: 7,2 percent). Irregular antibody rate associate with transfusion times (no transfusion: 1,2 percent, less than 5:times: 3,8 percent
from 5 to 10 times: 6,2 percent
more than 10 times: 9,8 percent). Thalassaemia patients patients have the highest irregular antibody rate (11,5 percent). Conclusions: Irregular antibody rate of blood diseases patients is 5,7 percent. The highest irregular antibodies rate was found in Rh blood group system: 55,9 percent, anti-Mi of MNS blood group system made up 28,6 percent. Irregular antibody rate associate with sex and transfusion times. The highest irregular antibodies rate was found in thalassaemia patients.