Practice guidelines are standardized specifications for managing particular clinical problems and are intended to improve the outcomes of medical care by increasing adherence to standards of care. They are also meant to make medicine more cost-effective by eliminating unnecessary procedures. A relatively recent phenomenon, the practice guidelines now emerging will have implications for malpractice, which also intends to bring about better care. They will probably not revolutionize the procedures that courts use to determine negligence, but judges will integrate guidelines into their decision-making process. This development should be welcomed. Guidelines should prove to be useful as either inculpatory or exculpatory evidence of negligence. They are unlikely to generate much new litigation, although there is some potential for suits against those who issue guidelines, especially if guidelines are not revised as the technology of medical care changes.