Patients attending a dedicated dental clinic during the previous 24 months were assessed for the success of root canal treatment. Two groups, totalling 48 patients, had root canal treatment to 57 teeth performed by one operator. All treatment was carried out without antibiotic prophylaxis over two or more appointments. Patients with HIV infection had root canal treatment to 40 teeth. Sixteen patients in the control group had root canal treatment to 17 teeth. Short-term success was determined by follow-up appointments 1-3 months following obturation. No complications were experienced in either group, except with one HIV infected patient. The results of this clinical study indicate that root canal treatment can be carried out following standard procedures and without antibiotic prophylaxis.