Brucellosis is a multisystemic infectious disease with high morbidity rates. Despite improvement in laboratory techniques diagnosis and monitoring response to treatment may be difficult in brucellosis in endemic regions. Mean Platelet Volume (MPV) is an index of platelet activation and mentioned to be influenced by inflammation. This study was undertaken to compare MPV with acute phase reactants in acute and posttreatment phase of brucellosis with healthy controls.A total of 39 brucellosis patients (male/female: 15/24) and 40 healthy controls (male/female: 23/17) were enrolled study. Brucellosis diagnosis was based on clinical, serological and bacteriological data. MPV and inflammatory markers were measured at the time of diagnosis and at the end of the treatment.MPV levels of patients in acute phase were significantly lower than control cases ( p < 0.001). Overall accuracy of MPV in determining acute brucellosis was 75.2% with a sensitivity, specificity, NPV and PPV of 74.4%, 75%, 75% and 74.4% respectively (AUC:0.774). We suggest that MPV might help in assessment of brucellosis as an inexpensive and easy applicable test with other inflammatory markers.