History and Objectives: Considering the extensive use of heparin as an anticoagulant and because of the controversial reports on the prevalence of heparin-induced thrombocytopenia (HIT) in different studies, this study was conducted in the cardiology ward of Shaheed Beheshti hospital in Kashan to determine the prevalence of HIT.

Materials and Methods: The descriptive strategy of this study was carried out on 400 patients. Patients with a diagnosis of cardiovascular disorder were selected to consume heparin at an appropriate treatment dose and initially did not have thrombocytopenia and patients with such a condition were excluded from the study. Thereafter, cell count was conducted very two day.

Results: The study was performed on 400 patients with angina pectoris (65%) and myocardial infarction (35%) (67% out of them were male and the remainder (33%) was female). None of them showed signs of thrombocytopenia.

Conclusion: It appears that in contrast to results of other studies with an incidence of 30% for thrombocytopenia, this complication is a rare one and it is not essential to conduct expensive and troublesome methods of platelet counts for related patients.