Colonoscopy plays a pivotal role in colorectal cancer (CRC) screening and reduces CRC incidence and mortality. Its effectiveness depends on colonoscopist performance, which can vary.Missed lesions during colonoscopy can lead to post-colonoscopy CRC (PCCRC), making highquality colonoscopy essential for maximizing the preventive benefit of CRC screening. This review highlights the significance of colonoscopy quality indicators and practices for improvement.Bowel preparation, cecal intubation, and withdrawal time are key process indicators for procedure quality and are closely associated with the adenoma detection rate (ADR) and PCCRC risk.Given the role of colonoscopy in preventing CRC through the removal of precancerous lesions, the ADR serves as the core quality metric and the most reliable predictor of PCCRC. Serrated polyps have gained attention in colonoscopy quality research, as 15% to 30% of CRCs arise from serrated lesions, with an increased detection rate inversely associated with PCCRC risk. This emphasizes the critical need for continuous efforts by colonoscopists to enhance performance quality. Systemic interventions, audits and feedback during endoscopist education, basic and enhanced withdrawal and inspection techniques, and technologies such as mucosal exposure devices and computer-aided detection have demonstrated efficacy in increasing the ADR. While artificial intelligence has shown promise in increasing the ADR, inconsistent outcomes in realworld studies underscore the continued importance of the fundamental aspects of high-quality colonoscopy techniques, including complete mucosal exposure. Understanding quality indicators and ensuring high-performance quality in daily practice will ultimately lead to better CRC prevention outcomes.