Fatigue, though a common complaint, presents a challenge to nurse practitioners who must evaluate its significance in the primary care setting. Fatigue is described as a multidimensional phenomenon and is classified as physiologic, acute, or chronic. A distinction is made between chronic fatigue and chronic fatigue syndrome (CFS). The use of the Piper Fatigue Scale is suggested in order to objectively quantify this symptom in clinical practice. In this article, the Habit and Lifestyle Form for the Evaluation of Fatigue is presented as a way to assist the provider in considering simple and obvious causes of fatigue that may otherwise be overlooked. Finally, an algorithm for the evaluation of fatigue is presented.