Fifty-three patients were treated for palliation with endoscopic neodymium yttrium aluminum garnet (Nd:YAG) laser for colorectal carcinoma at Roswell Park Cancer Institute. There were 25 females and 28 males. The mean age of the patients was 76 years. Thirty-eight tumours were primary and 15 recurrent. The level of the lesions from the anal verge ranged from 2 to 50 cm, with a mean of 10 cm. Eighty-four percent of the lesions were rectal carcinomas within 15 cm of the anal verge. Lesion length ranged from 1.5 to 12 cm with a mean of 5 cm. The number of laser treatments ranged from 1 to 17 with a mean of 3. The duration of treatments ranged from 25 to 90 min with a mean of 35 min. The mean number of joules per treatment was 5093. Eight patients (15%) developed complications. There were no mortalities. The success rate for treating bleeding, the most frequent presenting symptom, was 93%. The overall success rate of patients improved by laser treatment was 79%. Patients who were improved by therapy had a median survival of 18 months versus those not improved who had a median survival of 3 months (P = 0.01). The use of the Nd:YAG laser for palliative treatment of patients with colorectal carcinoma is safe, effective and associated with no mortality.