We evaluated the efficacy of palliative radiation therapy using 5 × 4 Gy given daily in 18 dogs with nasal tumors. Dogs with malignant nasal tumors were evaluated for response rate, response duration, and survival. Seventy-eight percent of the dogs achieved complete resolution of clinical signs, and 16.5% had partial resolution of their signs. Overall median response duration for all dogs was 178 days after one course of radiation therapy. Six dogs received a second course of therapy when their disease progressed using the same daily 5 × 4 Gy scheme, and all six responded for a median time of 129.5 days for an overall median survival time in these six dogs of 309 days. Based on these results, a radiation prescription of 5 × 4 Gy appears to be useful palliatively in dogs with a malignant nasal tumor.