This study was carried out on two groups of subjects who are attending general medicine outpatient department in Al-diwaniya teaching hospital & some privet clinic during the period from September 2011 to October2013 . the age range of both group was 35- 70 years of both sexes . The Control group consist of normal 285 healthy subjects ,including 188 males and 97 females while the patients group consist of 210 patients who are suffering from hypertension of which 125 male & 85 females. determination of blood group using antisera was done for each subject. It was founded that blood group O is more predominant among hypertensive patients , no significant difference was founded between both sex among hypertensive patients.
