Immunotherapy with interleukin 2 and lymphokine-activated killer cells can result in regression of metastatic cancer. Dermatologic complications associated with this therapy include erythema, pruritus, and a mild desquamation. Three patients with a history of psoriasis received high-dose interleukin 2 alone or in conjunction with lymphokine-activated killer cells for treatment of metastatic renal cell carcinoma. Two patients developed an erythrodermic exacerbation during therapy while the third patient experienced a localized flare. Topical treatment was effective in inducing remission in all three patients. Histologic analysis of serial skin biopsy specimens revealed psoriasiform changes in involved skin as well as epidermal spongiosis and a perivascular mononuclear cell infiltrate. The psoriatic exacerbation from interleukin 2 did not affect antitumor response to the therapy and should not be considered a contraindication to treatment.