The responsiveness of seminal vesicles and coagulating gland to androgen-induced growth at adulthood is enhanced in male rats that had been "primed" with androgen (either endogenous or exogenous) during the neonatal period. The neonatal "priming," however, did not significantly affect the basal (unstimulated) wet weights or DNA contents of the sex accessory glands when assessed at adulthood. In contrast to seminal vesicles and coagulating gland, the responsiveness of ventral prostate to the adult androgen-induced growth is independent of neonatal exposure to either endogenous or exogenous androgen. Our studies indicate that the neonatal androgen-induced "priming" or "programming" for androgen sensitivity of sex accessory glands at adulthood may not be associated with DNA synthesis as elicited by androgen during the neonatal period. For example, xyproterone acetate, an antiandrogen, effectively blocked the DNA synthesis in the seminal vesicles and coagulating gland of the neonatal rats without affecting the neonatal "priming" of the responsiveness of these glands at adulthood. Although only seminal vesicles and coagulating gland but not ventral prostate are "programmed" by neonatal exposure to androgen, this androgen-induced enhancement of [3-H]thymidine incorporation in to the DNA of the former was to the same degree as the latter. Furthermore, pulse-labeled cells in all of these glands studied persisted to adulthood to the same extent.