Thrombocytopenia in pregnant women may result from a number of diverse etiologies. While some of these are not associated with adverse pregnancy outcomes, others are associated with substantial maternal and/or neonatal morbidity and mortality. However, specific therapies, if instituted promptly, may significantly improve the outcomes of affected patients and their offspring. Since the clinical features of many of these disorders often overlap, identifying a specific cause of thrombocytopenia in a pregnant patient may be difficult. However, through familiarity with the more common clinical and laboratory features of each of these disorders, accurate diagnosis may be achieved, and appropriate treatment instituted in most cases. In this review, we discuss the differential diagnosis of the more common causes of pregnancy-associated thrombocytopenia, and provide an overview of approaches to hematologic management.