Background: the classification of molar gestations into complete and partial hydatidiform moles and their differentiation from hydropic abortion are traditionally accomplished by histomorphology alone, but sometimes, the process may be inaccurate or inconclusive. Recently, immunohistochemical staining techniques have been reported as a good diagnostic adjunct complementary to histologic diagnosis. One of the advantages of this method is the ability to apply it retrospectively to sections of routinely formalin fixed/paraffin embedded tissue and therefore, there is no need for expensive or sophisticated techniques. Aim of the Work: this study aimed to determine if immunohistochemical expression of p53, p63, p57 and Ki67 could aid in differentiating molar from non molar pregnancies on one hand and complete mole from partial mole on the other. Materials and Methods: a total of 180 placental specimens were enrolled in this study including 60 non molar placental specimens with hydropic changes and 120 molar specimens (60 complete hydatidiform moles (CHM) and 60 partial hydatidiform moles (PHM). These cases were examined histologically and immunohistochemically for expression of p53, p63, p57 and Ki67. Results: there was a significant difference in p57 expression between HA and PHM (P value < 0.05) and also between PHM and CHM (P value < 0.003). There was a significant difference in Ki67 expression between HA and PHM (P value < 0.03), PHM and CHM (P value < 0.01) and between HA and CHM (P value < 0.009). There was no significant difference in P63 expression between HA and PHM (P value ˃0.8), PHM and CHM (P value ˃0.5), and also between HA and CHM (P value ˃0.2).  A significant difference in p53 expression between HA and CHM (P value < 0.007) was noted, also between PHM and CHM (P value = 0.005), while no significant difference between HA and PHM in expression of p53 (P value ˃0.8).