Background and Aims In the past, the invasion of major vessels (such as the portal vein and inferior vena cava) was considered a contraindication for radical resection of intrahepatic cholangiocarcinoma (ICC). With advancements in surgical techniques, the safety of liver resection combined with vascular resection and reconstruction is gradually being recognized, but its efficacy remains inconclusive. Therefore, this study was conducted to investigate the safety and efficacy of liver resection with vascular resection and reconstruction for ICC patients with vascular invasion and the value of postoperative adjuvant therapy using multi-center data from domestic institutions.Methods The clinicopathologic data of 1 040 ICC patients who underwent radical resection between January 2010 and June 2021 in 12 grade A tertiary hospitals in China were retrospectively collected. This cohort included 872 patients without vascular invasion and 168 patients with vascular invasion (among whom 35 underwent combined vascular resection and reconstruction, and 133 underwent conventional radical ICC resection without vascular resection). Overall survival (OS) was analyzed for the entire cohort and patient subgroups. The impact of vascular resection and reconstruction on major clinical variables and OS of patients with vascular invasion and the influence of postoperative adjuvant therapy on OS were analyzed.Results The median OS for the entire cohort was 18 (9.4-30.6) months. The median OS for patients without vascular invasion was 18.51 (10-32) months, while for patients with vascular invasion, the median OS was 16.3 (9.4-28) months for those without vascular resection and 10 (5.5-21.6) months for those with vascular resection and reconstruction. Survival analysis indicated that patients with vascular invasion had lower OS than those without vascular invasion, regardless of whether vascular resection was performed (all P<0.05). Vascular resection and reconstruction did not significantly improve OS for patients with vascular invasion (P=0.662). After 1∶1 propensity score matching, the median OS for patients with vascular invasion remained lower than those without vascular invasion, but the differences were not statistically significant (non-vascular invasion vs. vascular resection: 26 months vs. 21.8 months, P=0.087; non-vascular invasion vs. non-vascular resection: 27 months vs. 16 months, P=0.068), and vascular resection and reconstruction did not significantly improve OS (P=0.293). Among patients with vascular invasion, vascular reconstruction led to longer operative time and length of postoperative hospitalization than those without vascular resection (all P<0.05). In contrast, other clinical variables, such as postoperative complications, showed no significant differences (all P>0.05). Subgroup analysis of patients with similar types of vascular invasion indicated that vascular resection and reconstruction did not improve OS for patients with different kinds of vascular invasion (all P>0.05). Regardless of whether vascular resection and reconstruction were performed, postoperative adjuvant therapy positively impacted OS, but the differences were not statistically significant (both P>0.05).Conclusion Vascular invasion is a prognostic risk factor for ICC patients, and vascular resection plus reconstruction does not significantly improve patients' prognosis, possibly leading to longer operative time and length of postoperative hospitalization. Postoperative adjuvant therapy for ICC patients with vascular invasion may help improve prognosis.