Introduction: Homocysteinemia is currently regarded as an independent risk factor in venous thrombosis and vascular diseases. So noticing its causes and risk factors in high risk populations, such as elderly and chronically ill patients is of much importance. This research is designed, considering the important role of homocysteinemia and the lack of statistics and adequate information about the prevalence of this disease among hospitalized patients in ICU.Materials and Methods: The is a descriptive, cross-sectional study, done by census sampling method on patients admitted in ICU of Rasoul-Akram hospital, during a 6 months period. Epidemiologic data was collected from the patients' files. A blood sample was taken from the patient to measure homocysteine level. Data was introduced using descriptive statistics.Results: 52 patients with the mean age of 58.42 were included in this study. Among these, 12 (23.1%) had a high homocysteine level and the other 40 patients (76.9%) had a normal range of homocysteine. The mean homocysteine level in patients with normal levels was 9.28(3.08-15.48) micromol/dl and the mean in patients with homocysteinemia was 21.05(11.05-31.05). Among patients with homocysteinemia, 25% had renal failure and 25% were presented with cerebrovascular accident (CVA). There was no significant difference between homocystein level in patients with renal failure and those with CVA.Conclusion: According to the 23.1% frequency of hyperhomocysteinemia in hospitalized patients of our study, also considering the Folate and vitamin B6 and B12 role in homocysteinemia, and also due to previous epidemiologic studies, it seems that evaluating Folate, vitamin B6 and B12, creatinine clearance and plasma albumin level may clarify the role of these factors as the probable predictive factor in patients with homocysteinemia.