Objective: The present study aimed to investigate the possible postnatal effects on the liver, kidney and testicular tissues of the offspring of rats given diclofenac sodium (DS) during pregnancy. Methods:At the beginning of the experiment, 80 rats (20 males and 60 females) were raised together for mating purposes. At the end, 50 pregnant rats were obtained and used as the experimental subjects. All pregnant rats were divided into 2 groups, each with 25 rats. The rats of the control group received physiological serum, 1 cm(3)/kg live weight per day, and the rats of the treatment group were injected with DS, 1 mg/kg live weight per day from the 5th to the 20th day of pregnancy. Four weeks after birth, tissue samples were obtained under anesthesia by perfusion fixation from a total of 40 offspring, 20 (10 males, 10 females) from the control group and 20 (10 males 10 females) from the DS group. Paraffin sections were dyed with hematoxylin eosin and examined under light microscopy. Results: The gestation period was significantly prolonged with DS-treated rats (p < 0.001). A moderate significant enlargement in the periportal area (p < 0.05), sinusoidal dilatation (p < 0.001), bile duct proliferation (p < 0.001), pyknosis in the nucleus of hepatocytes, and vacuolar degeneration in parenchymal cells (p < 0.001) were observed in DS-treated rats. Morphological changes in the liver were found to be similar both in female and male rats. Under light microscopy a similar morphological structure was observed in the kidney and testicular tissues of both the DS-treated and control rats. Conclusion: Significant morphological changes were observed in the livers of the offspring whose parents had been treated with DS. No significant differences were observed in liver morphology between the female and male offspring. There were no significant effects of DS on the morphology of the kidney and testis in all offspring. Copyright (C) 2001 S. Karger AG, Basel.