BACKGROUND AND HYPOTHESIS: Knowledge regarding access to first kidney transplantation (KT) and subsequent KT in patients commencing kidney replacement therapy (KRT) in childhood is limited. METHODS: Using European Renal Association (ERA) Registry data, we investigated European patients who started KRT below 20 years of age between 1978 and 2019. Access and determinants to first, second and third KT were assessed using multivariable Cox regression. RESULTS: 12 623, 4077, and 1186 patients were included while awaiting first, second and third KT, at median ages of 13.8 (IQR: 7.5-17.4), 20.9 (IQR: 16.5-26.1) and 26.6 (IQR: 20.3-32.8) years, respectively. During the study period, overall access was 87.8%, 72.7% and 60.5% for first, second and third KT, respectively, and median time to each KT was 0.9 (IQR: 0.2-2.1), 1.9 (0.6-4.5) and 2.6 (IQR: 1.0-5.3) years. Younger age at KRT initiation (aHR 0-4 vs. 10-14 years: 0.54; 95%CI: 0.51-0.57) and female sex (HR: 0.94; 95%CI: 0.90-0.98) were associated with lower access to first KT. KT candidates between 15-19 years had lower access to first and second KT (aHR: 0.69; 95%CI: 0.66-0.73, and aHR: 0.70; 95%CI: 0.61-0.81) compared to 10-14 year-olds. Compared to CAKUT, glomerulonephritis patients had lower access to KT (aHR: 0.75; 95%CI: 0.71-0.80 for first, aHR: 0.89; 95%CI: 0.81-0.98 for second and aHR: 0.80; 95%CI: 0.66-0.97 for third KT). Similarly, patients with primary renal diseases with high risk of recurrence, had lower chances of receiving a first and second KT (aHR: 0.80; 95%CI: 0.76-0.85 for first, aHR: 0.86; 95%CI: 0.78-0.95 for second KT). Access to re-transplantation was also higher with prior pre-emptive KT and previous graft survival exceeding five years. CONCLUSION: Our study highlights KT access disparities particularly for females, the youngest recipients, high-risk age (15-19 years), and diseases with recurrence risk. Notably, pre-emptive transplants and enduring previous grafts offer advantages regarding re-transplantation.Read less <