Background: Factor V deficiency (FVD) is a rare bleeding disorder (RBD) mostly present in regions with a high rate of consanguinity. FVD after FXIII deficiency is the next more prevalent RBD in Sistan and Baluchistan (S&B) in southeastern Iran. The aim of this study was to evaluate the clinical manifestations and severity of bleeding diathesis in patients with FVD. Methods: This descriptive study was conducted on 23 patients with FVD in S&B province. FVD was diagnosed by clinical findings and routine laboratory tests. Bleeding diatheses were classified into three grades (I-III) depending on the severity of symptoms. The severity of bleeding episodes in our patients was compared with other RBDs. Result: Based on residual plasma FV activity, 6 (26%), 16 (69.5%) and 1 (4.5%) patients had mild, moderate and severe factor deficiency, respectively. 24% of the patients had grade III life-threatening bleeding episodes which in comparison with FVII deficiency (17.4%) and FI deficiency (21%) had a higher incidence, and in comparison with FX deficiency (41.7%) and FXIII deficiency (63.1) had a lower incidence. Grade II and grade I bleeding diathesis were observed in 56.2 and 16.7% of the patients, respectively. Conclusion: FVD is the second most common type of RBD in S&B province and grade II bleeding episodes were the major bleeding presentation and observed in more than half of the patients.