This study aimed to determine the protective role of l-ascorbic acid in a pregnant rat model of cadmium-induced toxicity. Cadmium is a toxic heavy metal that can seriously harm placenta and fetus tissue in pregnant women. Forty-two healthy female Wistar albino rats (250-300 g weight and 14-16 weeks) were randomly distributed into six equal groups (n = 7): control, cadmium 1 mg (CD1), cadmium 5 mg (CD5), ascorbic acid (AA), CD1+AA, CD5+AA. Cadmium was administered to pregnant rats by oral gavage every other day, and/or AA (200 mg) was administered every day. At the end of pregnancy (Day 21), blood, placenta, and fetuses were collected from rats. The results indicated that cadmium-induced oxidative stress by increasing the level of MDA and by decreasing the levels of GSH, SOD, and CAT activity in the serum of maternal. However, AA administration significantly decreased MDA levels and increased GSH levels, SOD, and CAT activity (p < 0.05). Cadmium (5 mg/kg) exposure significantly increased creatinine levels compared to AA and CD1+AA groups (p < 0.05). In addition, AA (200 mg/kg) significantly attenuated cadmium-induced histopathological alteration in the placental and fetal tissues. In conclusion, AA may prevent cadmium toxicity in maternal and fetal tissues, as it regulates oxidative imbalance in pregnant rat tissues and alleviates histopathological changes.