Objective: To assess the occurrence and severity of thrombocytopenia in hospitalized vivax malaria patients.Design and setting:Retrospective and descriptive hospital based case series from March 2005 to March 2007, conducted in the medical unit of Al Khor Hospital.Patients and methods: 78 patients with peripheral smear positive were enrolled in the study. Peripheral smear examination for malaria parasites was used as the method of choice for the diagnosis of malaria. Hematological parameters were determined by using an automated analyzer. Low platelet counts were re-evaluated by manual methods.Results:Study sample was 78 patients, of which 65 patients (83.3%) were thrombocytopenic. Of these, 41 patients (52.6%) had mild thrombocytopenia, 23 patients (29.5%) had moderate thrombocytopenia and 1 patient (1.3%) had severe thrombocytopenia. All patients (100%) were male.Conclusion:High prevalence of thrombocytopenia was seen in vivax malaria patients, making it a common hematological feature in vivax malaria.