Interferon-gamma (IFN-a) autoantibody syndrome is an emerging clinical entity that has been associated with disseminated non-tuberculous mycobacterial infection (dNTM) particularly in healthy young people, a population not previously thought to be at particular risk. A 29-year-old South-East Asian man presented with several weeks of fever, cough, lymphadenopathy, and constitutional symptoms while working on an international cargo ship, deteriorating rapidly with a sepsis-like syndrome. Eventually lymph node and sputum cultures revealed a diagnosis of dNTM infection with growth of both Mycobacterium persicum and Mycobacterium abscessus. He was commenced on rituximab as well as combination anti-mycobacterial therapy with good clinical response. This case highlights some of the difficulties faced by patients with dNTM in the context of IFN-a autoantibodies, particularly delayed diagnosis, and lack of evidence base surrounding optimal management. Further research into long-term outcomes and treatment is required as well as increased awareness among clinicians. Kulcsszavak: interferon-gamma antibodies, disseminated nontuberculous mycobacteria, Mycobacterium persicum, acquired anti-cytokine antibodies