Thirty-one patients with early mycosis fungoides (MF) and three patients with parapsoriasis en plaques were treated with ultraviolet phototherapy (280 to 350 nm) at home using a commercially available light source containing four Westinghouse FS40 lamps. A complete clinical and histologic remission of disease, lasting for a median duration in excess of 18 months, was achieved in nineteen patients (61%) with MF. Although higher complete response rates generally are achieved with other therapeutic modalities, ultraviolet phototherapy with its minimal adverse effects may be indicated for selected patients. Controlled studies are encouraged to evaluate the full potential of conventional phototherapy in the management of MF.