A study was made concerning the effects of sialoadenectomy and parotin hormone administration upon sponge-induced granulation tissue of young adult rats. The effects of sialoadenectomy alone and sialoadenectomy plus a single subcutaneous injection of parotin hormone, in two different doses (0.15 and 0.30 mg), on the development of 15-day-old granulation tissue were observed. The action of parotin hormone administration without sialoadenectomy was also investigated. The results have shown that sialoadenectomy produces a retardation effect upon the development of the tissue. This effect was partially inhibited by 0.15 mg and totally eliminated by the administration of 0.30 mg of the hormone. When administered in rats which were not síaloadenectomized, the dose of 0.30 mg caused increased fibroplasia and vascularization of granulation tissue, while a dose of 0.15 mg did not cause any significant difference when compared to the control tissue