A 42-year-old man developed leptomeningeal carcinomatosis 6 years after treatment of a malignant melanoma. He was treated with two courses of recombinant interleukin-2, administered as a continuous intraventricular infusion (6 X 10E5 U/24 h) during 5 days. During the first day of the first course he also received 5 X 10E9 lymphokine-activated killer cells intraventricularly. This gave rise to a severe elevation of intracranial pressure, with headaches and meningismus. During the second course no LAK cells were administered. This course was tolerated much better. The neurological status did not change during the treatment. Recombinant interleukin-2 levels were maintained at about 300 U/mL during both courses.