ABSTRACTAims were to reveal types of onasemnogene abeparvovec‐xioi (OA)‐induced liver injury, their treatment patterns, utilization of healthcare, and treatment costs. This study employed secondary research to analyze OA‐induced liver injury using data from the EudraVigilance database, published case reports, cohort studies, and clinical trials. The extracted data were analyzed to define real‐life clinical entities that could be clearly outlined as syndromes resulting from the OA‐induced liver injury, and further used in guiding the development of healthcare utilization matrices. Serbian healthcare costs were calculated by multiplying utilization figures by local unit prices, converted to Euros using exchange rates and adjusted by price level indices. A spreadsheet model with uniform distributions simulated costs for 1000 virtual patients, providing mean values and standard deviations for Serbia and the EU. From 1566 adverse event reports in the EudraVigilance database following OA therapy, 231 were hepatobiliary disorders, predominantly hypertransaminasaemia (30.7%; 71/231). Liver injury largely manifested as mild‐to‐moderate biochemical abnormalities, rarely progressing to severe complications, and was effectively managed with corticosteroid therapy. Economic analysis highlights the manageable burden of OA‐induced liver injury. In the EU, mild‐to‐moderate cases cost €823.7, while severe cases average €1638.6. Medication costs range from €26.8 for prednisone to €695.4 for severe cases requiring additional immunosuppressive agents like tacrolimus and mycophenolate mofetil. To conclude, OA‐induced liver injury, though notable, is clinically manageable with immunosuppressive therapy and rarely causes severe complications like encephalopathy or liver failure. Its modest costs do not undermine OA's cost‐effectiveness, supporting its transformative role in spinal muscular atrophy treatment.