The survival rate, physical development, and spontaneous behavior has been evaluated in pups of albino rats exposed to acute hypobaric hypoxia on the 9-10th day of gestation corresponding to the onset of organogenesis. Prenatal hypoxia increased the mortality among the offspring, delayed their physical development, and affected their spontaneous behavior up to the age of 2 months. The females exposed to intrauterine hypoxia proved to be more sensitive to hypoxia than males.