PURPOSE: Recently, the use of a transparent cap attached to the tip of the colonoscope has been revealed to be helpful in both detecting colorectal polyps and shortening the intubation time to the cecum. The aim of this study was to examine the usefulness of transparent cap-attached colonoscopy (CAC) as compared with conventional colonoscopy (CC) in terms of the technical ease and efficiency. METHODS: Colonoscopies from a total of 228 patients between May and October 2008 were prospectively collected. All colonoscopies were performed by single colorectal surgeon whose experience exceeded 3,000 colonoscopies. Patients were assigned to the CAC group (n=114) or to the CC group (n=114). The cecal intubation rate and time, the polyp detection rate, the adenoma detection rate, the withdrawal time, and the visual analogue scale (VAS) of the patient's pain were compared. RESULTS: There were no significant differences in the age, sex, body mass index, previous history of abdominal operation, diverticulosis, and the degree of bowel preparation between the two groups. The cecal intubation rate was 100% in both groups. The cecal intubation time was significantly shorter in the CAC group than in the CC group overall (5.3+/-4.0 min vs. 7.6+/-4.3 min, P<0.001), as well as for female (6.1+/-2.8 min vs. 9.1+/-4.7 min, P<0.001) patients. There were no statistically significant differences in the total colonoscopy time (13.1+/-6.3 min vs. 14.5+/-5.2 min, P=0.066), the polyp detection rate (38.6% vs. 33.3%, P=0.408), the adenoma detection rate (28.1% vs. 25.4%, P=0.654), and the VAS scale of pain (2.48 vs. 2.74, P=0.353) between the CAC and the CC groups. CONCLUSION: The transparent cap is effective in shortening the cecal intubation time, especially in female patients.