BACKGROUND: Long-term changes in renal function following blunt kidney injury (BKI) remain insufficiently studied, particularly in patients who undergo renal artery embolization (RAE). The aim of this study was to clarify the long-term risks of chronic kidney disease (CKD) and dialysis in patients with BKI after unilateral nephrectomy, RAE, or conservative treatment. The hypothesis was that both unilateral nephrectomy and RAE would increase these risks compared with conservative treatment, with RAE posing a lower risk. METHODS: This retrospective cohort study used data from Taiwan's National Health Insurance Research Database from 2001 to 2019, focusing on patients with BKIs. Outcomes included long-term CKD risks, lifelong dialysis, and all-cause mortality. Inverse probability of treatment weighting was used to minimize confounding. RESULTS: During the study, 19 013 patients were diagnosed with BKIs; of these, 12 709 were analysed (unilateral nephrectomy, 274 (2.1%); RAE, 510 (4.0%); conservative treatment, 11 925 (93.8%)). The mean(standard deviation) age was 39.7(17.1) years, 69.4% were male, and the mean follow-up duration was 10.7(5.2) years. Compared with conservative treatment, patients undergoing unilateral nephrectomy (subdistribution hazard ratio (SHR) 1.97; 95% confidence interval (c.i.) 1.86 to 2.10) or RAE (SHR 1.17, 95% c.i. 1.09 to 1.26) had a higher risk of CKD. In addition, patients in the nephrectomy and RAE groups had an increased risk of lifelong dialysis, with an SHR of 3.97 (95% c.i. 3.09 to 5.10) and 1.46 (95% c.i. 1.07 to 1.99), respectively. Unilateral nephrectomy was associated with a higher risk of all-cause mortality than RAE and conservative treatment, with hazard ratios of 1.14 (95% c.i. 1.06 to 1.23) and 1.63 (95% c.i. 1.52 to 1.75), respectively. CONCLUSIONS: Patients with BKIs are at higher risk of long-term CKD and potential lifelong dialysis after both unilateral nephrectomy and RAE, with RAE presenting a lower risk than nephrectomy. Patients with BKIs who undergo unilateral nephrectomy or RAE require follow-up to monitor renal function and receive health education on kidney protection.