OBJECTIVE To assess the knowledge and clinical practice of dental students in infection control procedures at a UK dental hospital. METHODS A questionnaire concerning various aspects of infection control was completed by all clinical dental students under examination conditions. Their actual clinical practice was later observed and certain aspects recorded. METHODS A UK dental hospital. METHODS One hundred and eleven dental students from three clinical years completed the questionnaire. Clinical practice for all 3 years was observed in a total of 280 treatment events. METHODS The questionnaire was marked by two of the authors and observations recorded by another author. METHODS Degree of compliance with recognised policy for infection control. RESULTS Knowledge of infection control procedures was variable particularly concerning duties usually undertaken by the dental nurse. The suggested high compliance with masks and eye protection was not always apparent in clinical practice, although virtually all students washed their hands prior to donning gloves, which were worn by all students. CONCLUSIONS There can be marked differences between what students say they would do and what they actually do in clinical practice. The topic of infection control requires a pro-active approach throughout the course, since results for the final year were not significantly different from the other clinical years. Ways of improving compliance are discussed.