This study was carried out to investigate the toxicity of the oral administration of uranyl acetate on the activity of some vital organs. Twenty mature females and ten males of albino rats were used in this experiment. They were divided into four equal groups. The first group (G1) used as control received only distilled water, while the others administrated orally by (50, 75 and 100 mg/kg/b.w. /day of uranyl acetate) for 70 days (10 weeks). Lung was taken from the offspring at two age stages (3 rd and 5th weeks) for the current study.Rats exposed to different doses of uranyl acetate showed a significant (p<0.05) decrease in body weight (b. w) of the offspring at 3 rd week age, while b.w of the offspring revealed no significance at the 5 th week age.Furthermore, histopathological section of the lung of the offspring revealed the same lesions with differ severity according to the dose, including congestion in the pulmonary blood vessels specially branches of vein and in the alveolar capillaries, it was also showed, focal infiltration of mononuclear inflammatory cells (lymphocytes) and thickening of the alveolar wall in some area and infiltration of lymphocytes due to narrowing of the alveolar lumen (atelectasis) which lead to hyperplasia of the cellular elements.