Aim of the work: Buspar drug(buspirone) is an antianxiety agent for the treatment of anxiety, and there are no adequate studies of Buspar in pregnant women which made this issue an exciting research area; so that our aim was to study the effects of buspirone on the structure of pancreatic tissue of the maternally treated rat fetuses. Material and methods: Buspirone hydrochloride tablets were obtained from Beecham, Haram, Giza, Egypt. Animals were divided into three groups (Ten pregnant rats in each group). Group I: (The control group) pregnant rats administrated orally distilled water only; Group II: pregnant rats were given oral dosages of buspirone hydrochloride at a dose level of 0.27 mg/ 100g b.w./day, daily for 15 days from the 6 th day to the 20 th day of gestation; Group III: pregnant rats were treated with the same manner with buspirone hydrochloride at a dose level of 0.41 mg/ 100g b.w./ day for 15 days from the 6 th to the 20 th day of gestation. Samples were taken from pregnant rats of all groups which sacrificed at 20 th day of gestation and fetuses were picked out for histological, histochemical and immunohistochemical studies for pancreatic anti-insulin and caspase-3 monoclonal antibody markers. Results: Treatment of pregnant rats with buspirone showed histopathological alterations in the pancreas of their fetuses; these alterations were well marked in the high dose maternally treated fetuses, and resulted in deformity in the pancreatic tissues. Conclusion: The present study showed that administration of buspirone may result in several histological and immunohistochemical deformity in the fetal pancreatic tissues.