Abstract: A high incidence of thromboembolic events have been reported among thalassemia intermedia patients especially in splenectomized patients. This study has been conducted to evaluate the coagulation state of patients referred to thalassemia research center at Booali Sina Teaching Hospital, Sari, Iran. This descriptive- cross sectional study was performed in 2007. Sixty thalassemia intermedia patients aged older than 10 years were enrolled. After recording demographic and therapeutic data of the participants, the plasma levels of Coagulant factors were measured. Obtained Data were analyzed using SPSS 13 software and t-test and chi-square tests. Of 60 studied patients, 62% were female. The mean age of the patients was 26.6±9.3 years. ASA tablet were used in 53.3%. None of the patients have experienced thromboembolic events. Decrease in protein C has been observed in 60%. Antithrombin III was decreased in 42% and protein S declined in 10% of the patients. Mutation in factor V leiden was seen in 3%. Splenectomy performed in 53.3% and there was no significant relation between low level of protein C and protein S, antithrombin III and presence of factor V leiden with splenectomy (p>0.05). Regarding to the high incidence of low levels of protein C, protein S and antithrombin III among thalassemia intermedia patients, there is an increased risk of thromboembolic events in the patients.