The aim of this work was to evaluate the effects of cadmium on the ovarian parenchyma. An experimental study was designed with 25 Swiss albino mice (healthy females) living 50 days under controlled laboratory conditions. For the experimental group, 21 mice were selected at random and divided into 3 groups (B, C, and D) of 7 animals each; thereafter they were exposed, respectively, to 50, 100 and 150 ppm of cadmium chloride dissolved in water offered ad libitum. They were compared with the control group A (6 remaining mice). Beginning on week three, physical and behavioral changes were observed: darkening of the eyes, yellowish discoloration of hair, flaccid and hypotonic muscles, irritability, aggressiveness and indifference. Ovaric histological findings were compared among the groups through optic microscopy and they were the following in cadmium exposed mice: 1) in the epithelium, proliferation, finger-like projections, hyperplasia, degeneration and necrosis; 2) in the ovary cortex, increased numbers of atresic follicles, decreased number of follicles in different stages of maturation, disorganization, edema and decreased number of yellow bodies; 3) in the interfollicular zone, areas of disorganization, edema and necrosis, mainly in the samples belonging to group D; 4) in the ovaric medulla, congestion, hyperemia and large sanguineous vasodilatation tending to haemorrhage. Since these effects increased with increasing concentrations of cadmium chloride, we may conclude that cadmium chloride is a highly toxic agent on the ovaric parenchyma of Swiss albino mice.