We studied prothrombotic determinants, namely protein C, protein S, and AT along with factor V Leiden (1691G-->A), prothrombin gene mutation (20210G-->A), CBS 844ins68 mutation, and MTHFR mutation (677C-->T) in consecutive ethnic Omani patients with first episode of a thrombophilic event, namely, deep vein thrombosis (DVT), and/or pulmonary embolism (PE) or thrombosis at an unusual site.