Objective: To observe the expression of adhesion molecules VCAM -1, ICAM -1 in placentas of infants with low birthweight 21 placentas of patients treated at the University Hospital North in the period from May to December were studied 2006. Materials and methods: Macroscopic study of the placentas was performed; shape, weight, diameter, thickness, consistency, color, and odor: For five cuts microscopic studies chorionic plate, one membrane roll and another cord were performed. The sections were fixed in 10 % formalin, embedded in paraffin, stained with hematoxylin-eosin for morphological studies. For immunohistochemical studies monoclonal antibodies were used castra nova for ICAM1, VCAM1, macrophages. Results: 18 placentas round, three oval, the various weight between 240-400 grams, 3 had infarction in the cotyledons. In the micro 18 presented hyaline medial necrosis, hyperplasia of the intima, xanthomatous macrophages, lymphocytic infiltrate in three . In the immunohistochemical expression of ICAM-1, VCAM-1 was observed in the basal of chorionic villi in the basal blood vessel and macrophages in stroma. Conclusions: cases changes are compatible with pre -eclampsia, three viral process. The expression of adhesion molecules and macrophage in immunohistochemistry suggests that these molecules are critical in the pathophysiological process of the placenta.