Endothelin receptor antagonist (ERA) therapy‑induced increase in liver transaminases in patients with pulmonary arterial hyperten sion (PAH) is an adverse effect of bosentan which is not fully understood. A 62‑year‑old female with a 1.5‑year history of progressively worsening dyspnoea was diagnosed with idiopathic PAH (IPAH). After 2 months of PAH treatment with bosentan, levels of liver transami nases were elevated and autoimmune hepatitis was diagnosed. This clinical case demonstrates the challenge of diagnosing autoimmune hepatitis induced by ERA therapy in clinical practice. A thorough understanding of the pathogenesis and clinical presentation of autoim mune hepatitis, as well as the possibility to perform specific investigations with multiple serological markers are crucial for establishing the correct diagnosis