Objectives To assess the effects of nursing record systems on nursing practice and patient outcomes. Search strategy We searched The Cochrane Library, the EPOC trial register (October 2002), MEDLINE, Cinahl, Sigle, and databases of the Royal College of Nursing , King's Fund, the NHS Centre for Reviews and Dissemination, and the Institute of Electrical Engineers up to August 1999; and OCLC First Search, Department of Health database, NHS Register of Computer Applications and the Health Visitors' Association database up to the end of 1995. We hand searched the Journal of Nursing Administration (1971-1999), Computers in Nursing (1984-1999), Information Technology in Nursing (1989-1999) and reference lists of articles. We also hand searched the major health informatics conference proceedings. We contacted experts in the field of nursing informatics, suppliers of nursing computer systems, and relevant Internet groups. To update the review the Medline, Cinahl, British Nursing Index, Aslib Index to Theses databases were all searched from 1998 to 2002. The Journal of Nursing Administration, Computers in Nursing, Information Technology in Nursing were all hand searched up to 2002. The searches of the other databases and grey literature included in the original review, were not updated (except for Health Care Computing Conference and Med Info) as the original searches produced little relevant material. Selection criteria Randomised trials, controlled before and after studies and interrupted time series comparing one kind of nursing record system with another, in hospital, community or primary care settings. The participants were qualified nurses, students or health care assistants working under the direction of a qualified nurse and patients receiving care recorded and/or planned using nursing record systems. Data collection and analysis Two reviewers independently assessed trial quality and extracted data. Main results Eight trials involving 1497 people were included. In three studies of client held records, there were no overall positive or negative effects, although some administrative benefits through fewer missing notes were suggested. A paediatric pain management sheet study showed a positive effect on the children's pain intensity. A computerised nursing care planning study showed a negative effect on documented nursing care planning, although two other computerised nursing information studies showed an increase in recording but no change in patient outcomes. Care planning took longer with these computerised systems, but the numbers of patients and nurses included in these studies was small. A controlled before-and-after study of two paper nursing record systems showed improvement in meeting documentation standards. Authors' conclusions No evidence was found of effects on practice attributable to changes in record systems. Although there is a paucity of studies of sufficient methodological rigour to yield reliable results in this area, it is clear from the literature that it is possible to set up randomised trials or other quasi-experimental designs needed to produce evidence for practice. The research undertaken so far may have suffered both from methodological problems and faulty hypotheses. Qualitative nursing research to explore the relationship between practice and information use, could be used as a precursor to the design and testing of nursing information systems.