The availability of methods for early accurate identification of individuals at risk of developing adult polycystic kidney disease (ADPKD) has raised a number of important clinical problems. As part of a project on clinical and genetic aspects of ADPKD, we have assessed the knowledge and attitudes of patients and their families. Most had a poor knowledge of the condition and its implications. Despite this, many were in favour of early, including antenatal, diagnosis. A videotape was therefore introduced as part of an educational programme to improve patients' knowledge. This resulted in a marked improvement in understanding of the condition. Although a significant number still wished to consider early diagnosis in their offspring, very few would consider terminating an affected pregnancy.