Résumé : Individuals affected by melanoma with thick primary tumours or regional node involvement have a poor outlook, with only 30-50% alive at 5 years. High-dose and low-dose interferon alfa have been assessed for the treatment of these patients, with the former having considerable toxicity and a consistent effect on disease free survival, but not on overall survival, and the latter no consistent effect on either. Our aim was, therefore, to assess the effect of two regimens of interferon of intermediate dose versus observation alone on distant metastasis-free interval (DMFI) and overall survival in such patients.