Initial adjuvant immunotherapy trials have demonstrated a greater disease-free interval in patients treated with bacille Calmette-Guérin (BCG) compared with historical controls. In this study 149 patients at high risk of recurrence after surgical treatment of local or regional malignant melanoma were given BCG for 2 years and were followed up for a median of 28 months from the start of immunotherapy. The 36 patients in the comparison group had a higher rate of recurrence than the patients treated with BCG, and the rate in the treatment group was close to that reported from a similar study at the University of California at Los Angeles. The relatively long disease-free interval for the high-risk comparison patients in this study suggests that the control groups at other centres may have included patients with unrecognized additional risk. The rates of survival in the Canadian treatment group were also comparable to those reported by other centres. However, reports of a favourable BCG-mediated pattern of recurrence could not be confirmed. Therefore, the routine use of adjuvant BCG immunotherapy is not recommended.