This article addresses potential pitfalls and strengths of choline as a tracer in PET imaging. Choline acts as a precursor for the biosynthesis of phosphatidylcholine and other phospholipids. Because there is an increase in cell proliferation in cancers, the demand for phospholipids is high. This high content of phosphorylcholine in most cancers has been demonstrated with ³¹P nuclear magnetic resonance studies, whereas normal tissues have low levels. During the past decade the use of new PET tracers, namely ¹¹C- and ¹⁸F-labeled choline analogues, has been increasing. The physiologic pattern of choline-labeled radiotracer uptake and its related benign findings are reviewed.