['There are no data on how metabolic syndrome (MetS) affects the prevalence of synchronous colorectal neoplasm (CRN) in gastric neoplasm (GN) patients. The aim of this study was to investigate a model for risk stratification for colorectal screening by evaluating the clinical characteristics of synchronous CRN in GN patients classified according to the presence of MetS.', 'A cross-sectional, case-control study of 492 patients (368 males and 124 females) with GN, and 492 age-matched healthy controls undergoing simultaneous upper endoscopy and colonoscopy, was conducted.', 'The GN group involved 446 patients without MetS, and 46 patients with MetS. In total, 177 (39.7%) and 28 (60.9%) synchronous CRN were detected in GN patients without MetS and with MetS, respectively (P=0.006). A total of 143 (34.7%) synchronous colorectal adenomas were detected in GN patients without MetS, whereas 17 (48.6%) were detected in GN patients with MetS (P=0.101), as well as more synchronous colorectal cancers (11.2% vs 37.9%, P<0.001). A multivariate logistic regression analysis revealed that the presence of GN (OR=1.54, 95% CI: 1.18-2.00, P=0.001) and the presence of MetS (odds ratio=1.82, 95% confidence interval: 1.19-2.78, P=0.006) were significant independent risk factors associated with the prevalence of CRN. The frequency of synchronous CRN in GN patients with MetS was 1.96 times greater than that in the GN group without MetS.'] Is metabolic syndrome an independent risk factor for synchronous colorectal neoplasm in patients with gastric neoplasm?