Four years following resection of a Clark's level IV malignant melanoma, a 50-year-old man developed widespred metastatic disease involving the liver, bones, brain, gastrointestinal mucosa, and lungs. One week after whole brain radiation therapy, he was admitted to the hospital for nausea, vomiting, and pain. He was treated with several antiemetic drugs, but it was not until dronabinol was added that the nausea and vomiting stopped. Dronabinol was an effective antiemetic used in combination with prochlorperazine in nausea and vomiting unresponsive to conventional antiemetics.