Background: Causes of Cerebral Venous Thrombosis (CVT) varies around the world. Oral Contraceptive (OCP) are among the most frequent causes of CVT. Methods: Consecutive patients admitted with CVT in Ghaem hospital, Mashhad during 2005-2008 were prospectively investigated. Diagnosis of CVT was made by corresponding results of MRI, and MRV or conventional angiography. All of the patients had a complete medical history, physical examination and underwent a standard battery of diagnostic investigations by stroke neurologists.

Results: 62 patients (51 females, 11 males) with mean age 32.3 ranged 18-62 years were admitted with CVT. OCP consumption was found as risk factor in 56.8% of females with CVT. This group of females have been used LD and HD types of OCP in 97% and 3% respectively. 41% of females with CVT;(21/51) have been on short term OCP consumption. In this later group of females, Ramadan and Hadj religious months were the reason of using short term OCP in 86% and 5% respectively. Conclusion: Short term OCP consumption is the most common cause of CVT in Iranian women. Programs for public awarness should be conducted for reducing use of OCP in short term periods during Ramadan and Hadj months.