BACKGROUND: Longer cecal withdrawal time has been linked to a higher adenoma detection rate (ADR), with a minimum duration of 6 min recommended. Therefore, we developed the cecal withdrawal vocal timer (CWVT), a novel software tool that is command-activated at cecal intubation and vocally informs the endoscopist of the withdrawal duration every minute. OBJECTIVES: Evaluating the efficacy of the CWVT in enhancing adenoma detection. DESIGN: A retrospective, single-center study of screening colonoscopies with adequate preparation and documented cecal intubation. METHODS: The primary endpoint was the change in the department's ADR before (2022) and after the CWVT introduction (January 2023-February 2024). Secondary endpoints included the ADR change between procedures with and without CWVT after its introduction and the ADR change among individual endoscopists. RESULTS: The study included 1098 and 1330 eligible colonoscopies pre- and post-CWVT introduction, respectively. Following CWVT introduction, 67.3% of colonoscopies were performed with activated CWVT, with a median withdrawal time of 8.7 (interquartile range: 6.9-11.8) min. The department ADR was 25.5% following CWVT introduction, without a significant difference compared to the year before (26.2%,  = 0.71). During the post-CWVT implementation period, colonoscopies with activated CWVT had higher ADR than those without (28.4% vs 19.5%, respectively,  < 0.001). The improvement was mainly driven by the detection of adenomas smaller than 10 mm and was consistent across 11 out of 12 months in this period and among most endoscopists. CONCLUSION: While an overall ADR improvement was not achieved with the CWVT, the ADR was higher in post-CWVT procedures that utilized the CWVT than those that did not, warranting further prospective studies to evaluate CWVT's contribution to screening colonoscopy performance.