Chylous ascites (CA) after laparoscopic D3 lymphadenectomy for right colon cancer is not rare. However, the risk factors for CA have not been fully explored. Few studies have investigated the effect of CA on long-term prognosis.The clinical data of patients with right colon cancer who underwent laparoscopic D3 lymphadenectomy in five centers from January 2013 to December 2018 were retrospectively collected. Univariate and multivariate analyses were performed to determine the clinicopathological factors associated with CA. Then, the long-term prognosis of patients with and without CA was compared by propensity score matching and Kaplan-Meier survival analysis.The incidence of CA was 4.4% (48/1090). Pathological T stage (p = 0.025), dissection along the left side of the superior mesenteric artery (p < 0.001) and the number of retrieved lymph nodes (p < 0.001) were independent risk factors for CA. After propensity score matching, 48 patients in the CA group and 353 patients in the non-CA group were enrolled. Kaplan-Meier survival analysis indicated that CA was not associated with overall survival (p = 0.454) and disease-free survival (p = 0.163). In patients with stage III right colon cancer, there were no significant differences in overall survival (p = 0.501) and disease-free survival (p = 0.254).Pathological T stage, number of retrieved lymph nodes, and left side dissection along the superior mesenteric artery were independent risk factors for CA after laparoscopic D3 lymphadenectomy. CA does not impair the oncological outcomes of patients.© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.