Purpose: Biliary atresia (BA) is a progressive, obstructive cholangiopathy manifesting during early infancy. BA disproportionately affects Māori and Pacific Peoples, with previous studies reporting better outcomes among these groups. This study explores this and other predictors of outcome, in the largest study of BA in New Zealand (NZ) to date. Methodology: A retrospective cohort study including all patients with BA, born in NZ from 2002-2022. Cox proportional hazards regression was utilised to determine transplant-free survival (TFS) by sex, ethnicity, era (first 10 years versus last 11) and age at Kasai portoenterostomy (KP). Kaplan-Meier survival analysis was performed to demonstrate overall (OS) and TFS. Results: 148 patients (54% female) with BA were born in NZ during the study period. 60 patients (41%) were Māori, 28 (19%) Pacific Peoples and 18 (12%) Asian. OS and TFS at 5 years were 85% and 44% respectively. 5-year TFS was significantly better in Asian (63%), Māori (49%), Pacific Peoples (43%) compared to European (28%) patients. Median age at KP was 49 (European), 57 (Asian) and 62 days (Māori and Pacific Peoples). Sex and era were not associated with a difference in TFS. Conclusion: Outcomes for patients with BA in New Zealand are equivalent to other major centres. Māori, Pacific and Asian patients demonstrate better outcomes in spite of older age at KP. The reason for this remains unclear but provides further evidence for a difference in disease phenotype depending on ethnicity. This is an area that continues to be actively explored by this research unit.