Twenty-five patients with systemic malignancies or cutaneous disorders were treated with low dosages (1-16 IU/kg/day) of oral interferon-alpha in a phase-I study. There were no grade-3 or -4 toxicities. No patients achieved a partial or complete response. One patient with renal cell carcinoma had prolonged disease stabilization lasting for 22 months. No significant changes in lymphocyte subsets including T4/T8 ratio, or serum immunoglobulins were observed. Subjective improvement in general well-being was reported by three patients. Low dosages of interferon-alpha administered orally do not appear to have any significant immunomodulatory or antitumor activity.