Forty-two patients with metastatic renal cell carcinoma who were participating in a Phase II clinical trial were randomly assigned to an expressive writing (EW) or neutral writing (NW) group. Patients in the EW group wrote about their cancer, and patients in the NW group wrote about health behaviors. No statistically significant group differences were found in symptoms of distress, perceived stress, or mood disturbance, except for the Vigor subscale of the Profile of Mood States. However, patients in the EW group reported significantly less sleep disturbance, better sleep quality and sleep duration, and less daytime dysfunction compared with patients in the NW group. The results suggest that EW may have sleep-related health benefits in terminally ill cancer patients.