Thrombocytopenia is a common finding in normal pregnancy. The introduction of routine automated complete blood counting has clearly documented this. In the past, these patients would go undetected and be spared unnecessary testing, procedures, or medications. This article reviews the common causes of thrombocytopenia and offers criteria on which the diagnosis of clinically significant thrombocytopenia can be made. In addition, we will discuss therapeutic approaches to manage patients with pathologic thrombocytopenia.