Through adjuvant photon radiotherapy, it is possible to improve tumor control as well as avoid ultra radical surgery in patients with soft tissue sarcoma. Similar results have been obtained in cases of incomplete resected G1/G2 sarcoma after applying neutron radiotherapy. We compared the results of a group of patients with soft tissue sarcoma treated with those having received photon therapy (100 patients) or neutron therapy (61 patients). The median dose in the photon treated group was 60 Gy (range 45 to 65 Gy). The neutron therapy group received a median dose of 14.1 Gy (range 5.0 to 18.57 Gy). Patients treated with mixed-beam irradiation received an average dose of 36.5 Gy photon and 8.5 Gy neutrons. The 5-year survival rate of the photon group rated 43.1%. In the neutron group we found 42.5%, respectively. In both groups the results of surgical resection and grading were of high significance according to survival. 4% of the patients belonging to the photon group developed grade III/IV WHO side effects. In the neutron group side effects grade III/IV WHO were observed in 11% of the cases. Comparing treatment results of neutron and photon therapy we demonstrated that incompletely resected G1 and G2 tumor patients show greater benefit in the case of neutron radiotherapy.