Data came from a survey of all police agencies in England and Wales between November 1997 and May 1998 and detailed fieldwork in six agencies. Of the 43 agencies in England and Wales 36 had a tenure policy. Agencies varied with respect to the positions to which they applied tenure, categories used, regulations about transfers after completing a tenured post, the extent to which they apply tenure retrospectively, and the lengths of tenure attached to positions. In addition, the impact of tenure and police officers' perceptions of it differed across agencies. Opinions about tenure differed among police officers of all ranks and positions. Police regarded the creation of opportunities, balancing of skills, and prevention of stagnation in specialized departments as being worthwhile, but many questioned whether tenure was the most appropriate way to achieve these results. All the agencies reported problems with implementing their tenure policies. Police offers believed both that tenure would remain and that policies needed to change to retain credibility. Findings led to the development of a checklist for agencies to use as a guide to good practice when reviewing their tenure policies. Tables, figures, and checklist