Medical audit is now a well-established part of the routine of ophthalmology departments. Accomplishing a complete audit is a complex task and its effectiveness depends on how it is performed. In order to evaluate the procedure in our department a retrospective analysis of 18 audits was carried out with particular reference to the level, objectives, beneficial effects, and effects on current practice. Our practice was critically analysed using these factors. One audit fulfilled the criteria for a full audit. Eleven (60%) were partial or potential and six (30%) were an attempt in planning an audit. The majority omitted plans for implementing change or targets for future assessment. Seven had educational benefit. There was little effect on patient care, cost-effectiveness or communication. Medical audit can be clinically effective, educational and stimulating. Failure to complete all stages affects the outcome. This study identifies the difficulties involved in performing complete audits and suggests improving the procedure by auditing audits on a regular basis.