The study investigated the effect of calabash chalk on the uterus of adult female Wistar rats. The 15 female adult Wistar rats were randomly divided into groups A, B and C. Group A served as the control while groups B and C served as experimental groups. Their body weights were measured on a weekly basis throughout the experimental period. In addition to feed and water given to all groups, group A received distilled water only for 21 days, group B 40 mg/kg per body weight of non-salted calabash chalk for 21 days and group C 40 mg/kg per body weight of salted calabash chalk for 21 days. On the 22nd day the animals were sacrificed and their uterus harvested for histological studies. Data was analysed using one-way ANOVA and SPSS version 2.0. The body weight of animals in group B was significantly reduced (P<0.05) when compared to control group. The histological findings of the uterus revealed endometrial hyperplasia and presence of inflammatory cells in the group treated with non-salted calabash chalk and epithelial metaplasia coupled with endometrial hyperplasia in the group treated with salted calabash chalk. These hyperplastic and metaplastic effect could be attributed to the presence of lead in calabash chalk. Calabash chalk could cause histological changes in the uterus. Thus, prolonged or regular consumption of calabash chalk should be discouraged as it has been shown to have negative effect.