It has been suggested that an insertion/deletion (I/D) polymorphism in intron 16 of the angiotensin converting enzyme (ACE) gene may be associated with essential hypertension. The aim of this study was to examine the association between ACE I/D polymorphism with blood pressure level and hypertension status in Turkish type 2' diabetic subjects. Hundred and seven hypertensive (78 female, 29 male) and 132 normotensive type 2 diabetic subjects (73 female, 59 male) and 138 sex and age matched control subjects (87 female, 51 male) without diabetes and hypertension were included into the study. The I/D polymorphism was determined by polymerase chain reaction (PCR). There were no statistically difference in genotypic and allelic frequencies of the ACE I/D polymorphism between the hypertensive and normotensive diabetic patients and control subjects. Also no significant differences was detected in systolic and diastolic blood pressure among three different genotypes. ACE I/D polymorphism does not seem to play an important role in the development of hypertension in Turkish type 2 diabetic subjects, but prospective studies may show an association between ACE gene polymorphism and the development of hypertension in diabetic subjects.