This retrospective study evaluated the efficacy of radiotherapy used alone in macroscopic oral soft tissue sarcoma. Thirty-one dogs qualified for the study. Twenty dogs received curative radiotherapy (median total dose: 52.5 Gy) and eleven dogs were treated palliatively (3 x 8 Gy or 5 x 6 Gy). The time-to-progression for the curatively-treated dogs was 333 days versus 180 days for the palliatively-treated dogs (p=0.134). The overall survival was 331 days for the curative group and 310 days for the palliative group (p =0.2292). The results of this study suggest that radiation therapy is useful in the treatment of oral soft tissue sarcoma.