Despite the high prevalence of cancer-related fatigue and its documented negative effects on patients' quality of life, limited evidence is available to support interventions to prevent or treat cancer-related fatigue. Both pharmacologic and nonpharmacologic interventions have been tested, with aerobic exercise programs and anemia correction by erythropoietin demonstrating greatest effectiveness. This article reviews the available evidence and describes gaps in knowledge. Recommendations for future research on interventions for cancer-related fatigue are presented.