Approximately 1.3 million people in the United States will be diagnosed with cancer in 2003 and millions of other individuals are already living with the disease. Fatigue continues to be the most prevalent and disruptive symptom of cancer and its treatment regimens. Fatigue was the most frequent and distressing cancer-related symptom occurring in women with lung cancer, two times greater than the next symptom, pain, and remains one of the most common symptoms in newly diagnosed lung cancer patients at any stage of the disease. There are many causes of cancer-related fatigue including preexisting conditions, physical and psychological symptoms caused by cancer, and the consequences of cancer treatment. High levels of fatigue decrease quality of life, physical functional status, and symptom management. This article presents an evidenced-base review of cancer-related fatigue, strategies for the management of cancer-related fatigue, and recommendations for clinical practice.