The incidence of melanoma has been climbing steadily since the early 1970s. Although melanoma can be successfully cured by surgical excision in its early stages, it is the most common fatal form of skin cancer. The most critical factors in determining the prognosis for patients with melanoma are primary tumor thickness, ulceration and the status of regional lymph nodes. Surgical treatment alone is inadequate in patients with thick, ulcerated tumors and those with nodal disease, as shown by poor 5-year disease-specific survival rates. Despite the fact that high-dose interferon-alpha has been approved for the treatment of high-risk melanoma by the US Food and Drug Administration and regulatory agencies worldwide, current treatment recommendations vary widely due to the conflicting trial data and significant toxicity and cost associated with high-dose interferon-alpha.