Objective. To determine the present state of colonoscopic screening practice for patients at a high risk of developing colorectal cancer. Methods. We assessed colonoscopic screening practice in nine colorectal surgery or gastroenterology units referring patients to the regional genetics centre in the Northwest of England. The validity of the pedigree was confirmed by inspection of Hospital records, use of cancer registries and records of general practitioners across the United Kingdom. The screening activity at the participating centres was investigated by means of a questionnaire, site visit and study of case notes. Results. One hundred and eight high risk families were identified. Outside the genetics unit, family history was not taken in a structured manner and family pedigree was not confirmed. In four units screening was offered directly by the consultant surgeon. Differing protocols for screening were in place in six units, but were frequently not adhered to. Colonoscopy completion rates were known in only four units (range 83-97%). Frequency of screening varied from 2 to 5 years. Recording of information was minimal outside the patients' records and there were no dedicated databases. Facilities for families to be screened together existed in three units and the psychological effect of screening was not determined outside the genetics centre. Conclusions. Screening practice should be standardized and specific criteria met before regular screening is initiated. A dedicated database should be established to record information from units screening patients at high risk of colorectal cancer.