In utero exposure to di(2-ethylhexyl)phthalate (DEHP; 1000 mg/kg body weight) significantly decreased activities of testicular sorbitol dehydrogenase and acid phosphatase and increased gamma-glutamyl transpeptidase, lactate dehydrogenase and beta-glucuronidase activities at early ages. A decrease in the sperm count of the epididymal spermatozoa was also observed in the sexually matured animals of DEHP exposed group. The data suggest that in utero exposure to DEHP may affect the normal development of testes.