Objective: The aim of this study was to evaluate the most frequent placental findings in diabetes and hypertension and their main differences. Method: Retrospective study of 229 selected placentas from 19 to 41 weeks gestation, in a universe of 3231 placentas examined over the last 10 years (6 % associated with hypertension, 1,5 % with diabetes and 0,4 % with both diabetes and hypertension (DwH). Results: In diabetes the most frequently found abnormalities were immature villi (35 %) and infarction (27 %). In DwH the most frequent lesions were the immature villi (29 %) and inflammatory lesions (either acute or chronic) (29 %). In the hypertension group the most frequently found lesions were infarction (54 %) and accelerated maturation of the villi (23 %). In 35 % of placentas in diabetes, 21 % in DwH and only 15 % in hypertension, no lesions were found. The incidence of fetal death was 8 % in diabetes, 0 % in DwH and 5,5 % in hypertension. When evaluating placental weight, small placentas were more frequent in the hypertension group (37 %), and large placentas were more frequent in diabetes (27 %). Conclusion: Our findings may contribute to evaluate the consequences of diabetes and hypertension in fetal outcome.