Introduction: Colorectal cancer (CRC) is one of the most common cancers, and the Central European countries have the highest CRC burden worldwide. CRC screening has repeatedly been proven capable of decreasing CRC mortality and incidence rates. The nationwide Colorectal Cancer Screening Programme in the Czech Republic involves the colonoscopic examination as a diagnostic method (for patients with a positive FOBT result – screening colonoscopy – SC), or as a screening method (primary screening colonoscopy – PSC). The aim of this article is to present the results of colonoscopic examinations performed as part of the Czech screening programme. Material and Methods: For the purpose of quality assurance, the Czech programme has been equipped since 2006 with an information system called the Colorectal Cancer Screening Registry, which collects and evaluates data on preventive colonoscopies performed in the colonoscopy screening centres. Performance indicators, as specified in the European Guidelines (and adapted for the Czech programme), are employed to assess preventive colonoscopies performed in the Czech Republic. Results: Since 2006, more than 110,000 SCs and almost 20,000 PSCs were recorded. Approximately 95% of SCs and almost 98% of PSC were classified as total, i.e. examining the entire colonic mucosa up to the caecum. The positive predictive value of FOBT for adenomas has increased slightly and continuously over time, and was 39.7% in 2013. In PSC, the adenoma detection rate (ADR) has recently increased compared to previous years, and was 27.3% in 2013. CRC was detected in 3.7% of individuals undergoing an SC examination and in 1.0% of individuals undergoing a PSC examination. The programme safety is controlled based on the monitoring of complications during colonoscopies; these can occur either during diagnostic colonoscopy (perforation in 0.03% of cases since 2006) or during endoscopic polypectomy (perforation in 0.12% of cases, bleeding in 0.73% of cases since 2006). Conclusion: Our results confirm that the quality of colonoscopic examinations corresponds to the international standards and that this is not an obstacle to a positive impact of CRC screening on the Czech population, which has a high colorectal cancer burden.