BACKGROUND: Vitamin A is present in our food such as meat, dairy products, and vegetables. A control balanced diet maintains our nutritional needs of vitamin A. Over consumption of products as well as supplementations with vitamin A increases the risk of hypervitaminosis A. Hypervitaminosis A has been associated with thinning of the long bones and reducing of bone formation OBJECTIVES: to investigate the effect of over as well as optimum doses of vitamin A on growth of mandibular condyle in Wister albino rats. MATERIALS AND METHODS: Eight healthy (2month old age) male Wister albino rats weighting (274 -375grams) were used in present study. The rats were randomly divided into 2 equal group, study and control group .In the control group; rats fed a standard diet containing an optimum dose of vitamin A (12 IU/g of each pellet). In the study group, rats fed a standard diet supplemented with overdose of vitaminA (1700 IU /g of each pellet). After 2months, all rats were euthanized. Blood samples were collected from all rats the day after administering the last dose of vitamin and the concentration of vitamin A in serum was determined for all samples. The condyles of each rat of all groups were dissected out and processed for histological study and histomorphometric analysis. RESULTS: In the study group, the histological examination revealed marked reduction in thickness of hypertrophic zones and increase in the width of chondroblastic zones of condylar cartilage. Bone trabeculae were thin with irregular outline. The subchondral bone showed marked bone resorption with numerous osteoclasts in Howship's lacunae as compared with the control group. CONCLUSIONS: findings from the present study have indicated that, hypervitaminosis A increases resorption of the bone and diminishes endochondral bone growth.