The purpose of this study is to test the effect of partial muscle denervation on a tumor inocculated on the same muscle. Experiments were performed on male C57BL mice divided into two numerically equal A and B groups, each of which was subdivided into three subgroups AA, AB, Ac and BA, BB, BC, respectively. The right sciatic nerve of each mice of the A group was incised and partly dissected (day 0). Then Lewis lung carcinoma (LLC) cells were implanted on the right gastrocnemia of each mice of both groups on day 0 for subgroups AA and BA, on day 1 for subgroups AB and BB, and on day 4 for subgroups AC and BC. The incision and dissection of the sciatic nerve caused a significant reduction in the size of the tumor in all three A subgroups of mice. Fourteen days after implantation, the size of the primary tumors implanted on the right hind leg was 2.6 +/- 0.32 cm3, 3.5 +/- 0.21 cm3, and 4.7 +/- 0.31 cm3 for the three BA, BB, BC subgroups of the control group compared to 1.4 +/- 0.19 cm3, 2.0 +/- 0.28 cm3, and 3.0 +/- 0.27 cm3 for the three subgroups AA, AB, Ac, in which sciatic nerve was incised and dissected, indicating inhibition of the tumor growth of 46.2%, 43.0% and 36.2%, respectively. Although a smaller part of gastrocnemius is innervated by the anterior femoral nerve, which was left intact, denervation of the sciatic nerve caused inhibition of the tumor growth. This may be due to worse nutrition and/or blood supply of the LLC tumor. Mitochondria function and the degree of apoptosis of the tumor cells are further studied by us.