Thrombocytopenia (defined as platelet count 9/L) is present in 7% - 12% of pregnant women at delivery. Although there are mild etiologies of this condition that are often diagnosed incidentally, there are more severe causes that can be life threating. Thrombocytopenia also has a great implication in surgical risk and regional anesthesia. A structured evaluation of thrombocytopenia is necessary to allow an adequate diagnostic approach. Here we summarized the current knowledge of thrombocytopenia in pregnancy.