Abstract Background Treatment outcomes of incidental gallbladder cancer generally stem from tertiary referral centres, while many patients are initially diagnosed and managed in secondary care centres. Referral patterns of patients with incidental gallbladder cancer are poorly reported. This study aimed to evaluate incidental gallbladder cancer treatment in secondary centres, rates of referral to tertiary centres and its impact on survival. Methods Medical records of patients with incidental gallbladder cancer diagnosed between 2000 and 2019 in 27 Dutch secondary centres were retrospectively reviewed. Patient characteristics, surgical treatment, tumour characteristics, referral pattern and survival were assessed. Predictors for overall survival were determined using multivariable Cox regression. Results In total, 382 patients with incidental gallbladder cancer were included. Of 243 patients eligible for re-resection (pT1b–pT3, M0), 131 (53.9%) were referred to a tertiary centre. The reason not to refer, despite indication for re-resection, was not documented for 52 of 112 non-referred patients (46.4%). In total, 98 patients underwent additional surgery with curative intent (40.3%), 12 of these in the secondary centre. Median overall survival was 33 months (95% c.i. 24 to 42 months) in referred patients versus 17 months (95% c.i. 3 to 31 months) in the non-referred group (P = 0.019). Referral to a tertiary centre was independently associated with improved survival after correction for age, ASA classification, tumour stage and resection margin (HR 0.60, 95% c.i. 0.38 to 0.97; P = 0.037). Conclusion Poor incidental gallbladder cancer referral rates were associated with worse survival. Age, performance status, resection margin or tumour stage should not preclude referral of a patient with incidental gallbladder cancer to a tertiary centre. In this multicentre retrospective cohort study, the survival of 382 incidental gallbladder cancer patients treated in secondary care hospitals is reported. This paper gives surgeons guidance on the optimal patient trajectory for incidental gallbladder cancer patients. Patients’ age, performance status, resection margin or tumour stage should not preclude referral of an incidental gallbladder cancer patient to a tertiary centre.