Abstract Background Examining the current practice is important for the benchmarking of quality of colonoscopy and the comparison with the standards and recommendations expected by professional societies. Aim To describe colonoscopy practice in Italy, on the basis of prospective analysis of a large number of examinations performed by operators with different levels of expertise in a wide range of unselected centres. Design and setting Cross-sectional, prospective and multicentre study. Methods The main features of each endoscopy centre (structure indicators) were collected through the use of a standardised questionnaire. A second questionnaire was used to prospectively record details of all the consecutive colonoscopies performed in a 2-week study period. Results Data from 278 centres and 12,835 consecutive colonoscopies were evaluated. Centres were uniformly distributed throughout Italy – north, centre and south – as was their organizational complexity and workload. Overall, adequate facilities (i.e. cleaning area for disinfection/reprocessing, equipped recovery room), and safety equipment (i.e. pulse oximetry, equipment for emergency cardiopulmonary resuscitation) were lacking in a considerable amount of centres, especially in those with a lower degree of organizational complexity. Written informed consent was routinely required in 87% of the centres, but a specific consent for colonoscopy, including detailed information on adverse events, was adopted by 66%. Regular programs for recording some quality indicators (i.e. cecal intubation, quality of bowel cleansing, patients’ satisfaction and complications) were implemented in a minority of centres. About 93% of the colonoscopies were performed for diagnostic purpose; screening and surveillance accounted for 13.7% and 25.3% of the indications, respectively. Sedation and/or analgesia was administered in about half of the patients. Overall, colonoscopies were completed to the cecum in 80.7% of cases, and only 22.1% of the centres reported a cecal intubation rate ≥90%; this figure was reported in 33.1% of centres with high-organizational complexity and in 14.4% of outpatient units. The overall incidence of immediate complications was low (2 perforations, 26 bleedings and 32 serious cardiorespiratory complications). Conclusions This study documented a wide variation in colonoscopy practice between centres and highlighted problem areas where interventions are needed to improve performance and safety of the examinations.