In order to determine the prevalence of thrombocytopenia in pregnancy, a total of 1000 pregnant women with gestational age of 28 weeks or more attending Bahonar hospital in Kerman, Iran, were selected randomly. The gathered data were analyzed by EPI Info 6 software. The incidence of thrombocytopenia in pregnancy was 8.8%. The maternal mean age was 27.6± 6.1 with median 27. The mean of gravidity was 2.6±2 with median 2. The mean of parity was 1.3± 1.6 with median 1. The mean of gestational age was 36.5+3.5 weeks with median 37. The mean of abortion was 0.2±0.5 with median 0. The mean of still birth was 0.03±0.2 with median 0. There was a statistical significant relationship between thrombocytoenia and gestational age (P<0.04), Still birth (P<0.005), preeclampsia (P<0.0001), abruptio placenta (P<0.008), IUFD (P<0.01), systemic lupus erythematosus (P<0.0004), DIC (P<0.002), using methyldopa (p<0.002) and asprin (P<0.02). Therefore, it can be inferred that the incidence of thrombocytopenia in Kerman is more than other parts of the world and its relation with stillbirth, preeclampsia, abruption placenta, IUFD, systemic lupus erythematosus, DIC , using Methyldopa and Aspirin is worth considering.