BACKGROUND The introduction of quality assurance and medical audit has been an important development in general practice. However, the introduction of such programmes does not necessarily mean they are implemented by general practitioners. OBJECTIVE A study was undertaken to describe the problems and requirements perceived by general practitioners in relation to the implementation of quality assurance and medical audit in general practice. METHODS Interviews were carried out with a stratified sample of 120 Dutch general practitioners. Knowledge, acceptance and application of quality assurance and medical audit activities were investigated, and perceived problems and requirements in implementing quality assurance and audit activities were explored. RESULTS General practitioners in the Netherlands were generally positive towards quality assurance activities, but had little experience of carrying out such activities. The most frequently mentioned obstacles to implementing quality assurance activities concerned lack of time, colleagues' negative attitudes and fear of assessment and criticism by colleagues. Requirements for implementing quality assurance included having regular meetings with colleagues about quality assurance, having information on the aims and methods of quality assurance, having data from other practices with which to compare performance, having support in data collection, in audit in the practice and in setting up local peer review, and having financial support. The most important factor predicting the actual application of quality assurance activities was found to be knowledge of specific quality assurance activities. CONCLUSIONS Well-designed programmes for the implementation of quality assurance and medical audit, using a variety of different interventions, have to be developed. Such programmes should include the training of professionals in the concepts and methods of quality assurance as well as the provision of financial support for quality assurance activities.