This thesis is concerned with approaches used by the Scottish Programme for Clinical Effectiveness in Reproductive Health (SPCERH) to improve quality of care. The work embraces two main themes: understanding factors that influence clinical practice; and evaluating strategies to improve practice. Many factors influence practice, such as the nature of targeted behaviours, professionals and organisations (Chapter 1). An observational study, of practice related to 42 audit recommendations in 16 gynaecology units, found that attributes of recommendations independently modified the effects of a national audit and feedback project (Chapter 2). Four evaluations of dissemination and implementation strategies were conducted. The first, a telephone survey of 201 obstetricians and midwives, highlighted gaps in awareness of national recommendations on the prevention of material mortality (Chapter 3). The second, a before-and-after postal survey of 92 obstetricians, found mixed changes in self-reported practice following the dissemination of four national obstetric guidelines (Chapter 4). The third, an interrupted time series analysis, evaluated trends in the care of 1263 women in four maternity units related to of these guidelines, on mild, non-proteinuric hypertension in pregnancy (Chapter 5). No improvements in the appropriateness of initial investigations and subsequent clinical management were found. The fourth study, a cluster randomised trial involving all 26 gynaecology units in Scotland, evaluated a strategy to promote a guideline on induced abortion care. The strategy, delivered under the auspices of SPCERH, comprised audit and feedback, educational meetings, dissemination of a structured case record, and promotion of patient information. The strategy was refined in the light of barriers identified following a pre-intervention case record review, interviews with gynaecologists and a theoretically-derived survey of 151 clinical staff (Chapter 6). Post-intervention compliance with guideline recommendations was assessed by a review of 1474 case records and a survey of 1028 patients. No intervention effect was observed, possibly related to high pre-intervention compliance with selected recommendations and the appropriateness of the implementation strategy (Chapter 7).