Background: s/Aims: Calcium is a preventive factor for colorectal cancer, which develops from colorectal adenoma. This study aimed to investigate the association between dietary calcium intake and prevalence of colorectal adenoma among Korean adults. Methods: Overall, 612 participants aged ≥ 20 years who underwent gastrointestinal endoscopy at 8 medical centers from 2021 to 2023 were included. Dietary calcium intake was assessed using a food frequency questionnaire and was energy-adjusted using the residual model. Multivariate logistic regression models were used to calculate for the odds ratios (ORs) and 95% confidence intervals (CIs). The associations between dietary calcium intake and colorectal adenoma prevalence were also assessed according to the anatomic subsites and adenoma status (advanced or nonadvanced). Results: Among the 612 participants, 269 were diagnosed with colorectal adenoma (170 men and 99 women). With respect to the gender-specific association, low dietary calcium intake was associated with higher prevalence of colorectal adenoma among men (ORs [95% CIs]: 2.13 [0.50– 9.00] for < 250 mg/day; 3.53 [1.06–11.76], 250 to < 350 mg/day; and 1.84 [0.63–5.35], 350 to < 650 mg/day, compared to ≥ 650 mg/day of dietary calcium [p for trend = 0.07]). Similar association was observed among women, but neither the association nor trend was statistically significant (p for trend = 0.59). These inverse associations remained similar for distal colon/rectal adenoma among women and advanced adenoma among men. Conclusions Low dietary calcium intake was associated with high colorectal adenoma prevalence, particularly among men. Given the limited number of studies among Asian populations, our findings should be replicated in other Asian groups.