The Public Health Service (PHS) has undertaken a major effort to develop improved policies and procedures for dealing with misconduct in its research programs. Included in the definition of "misconduct" are the violation of Federal laws, regulations, or policies governing research or research training conducted, funded, or regulated by the Department of Health and Human Services; breaches of professional ethics that raise serious questions about an investigator's or institution's scientific or fiscal integrity; and serious failures to comply with other terms or conditions of an award. Recent incidents of falsification or misrepresentation of data and failure to comply with requirements for protection of human and animal subjects of research represent only a fraction of all research projects. However, they are troubling evidence that the traditional safeguards of science are not sufficient to prevent and detect willful wrongdoing. Research agencies, awardee institutions, and individual investigators have a collective responsibility to prevent misconduct in public research programs. The agencies and institutions, in turn, must deal promptly and equitably with allegations or evidence of misconduct. Individual research institutions and their professional organizations have developed policy statements affirming their responsibility for the integrity of the research enterprise and proposing specific procedures for dealing with incidents of misconduct. The National Institutes of Health currently serves as lead agency for a parallel PHS effort that includes a statement of general policies and principles, to be augmented by specific procedures for awarding agencies, regulatory agencies, and PHS intramural programs, as well as procedures for information sharing and joint investigations.