The purpose of this study was to evaluate the effect of dietary zinc levels during gestation on physical development of offspring. The statistical population consisted of adult male and female rats (Albino-Wistar) which were obtained from Pasteur Institute, Iran. After mating, 9 pregnant female rats were divided into 3 groups: 1) Zinc deficient group (0.050.05). There was a significant decrease in crown-rump length in zinc supplement as compared to control group (P<0.05), but there was no significant difference in brain growth (P>0.05). These findings suggest that zinc deficiency during the last three months of pregnancy impairs brain and physical growth of offspring and to impose enhanced zinc supplement during the last three months of pregnancy has negative effects on physical development.