The literature on sulfur amino acid metabolism is too vast for a short chapter to cover in great depth. I attempt here a brief overview with references to many specialized review articles. This review emphasizes aspects of sulfur amino acid metabolism elucidated in the last ten years, in particular aspects not generally covered in biochemistry texts, e.g. transaminative pathways of methionine metabolism. A selected list of reviews is given in references 1-15. References to reviews on glutathione are covered in the chapter by A. Meister in this volume (1a).