Adult-onset Still's disease (AOSD) is a chronic disease marked by seronegative arthritis accompanied by the involvement of the internal organs. Typical symptoms including fever, arthritis, joint pain, and a distinctive salmon-colored rash, often accompanied by pharyngitis, enlarged liver and spleen, enlarged lymph nodes, acute pancreatitis, peritonitis, pleuritis and pericarditis have been described together with various additional symptoms. AOSD is treated with nonsteroidal anti-inflammatory drugs, steroids, disease modifying drugs and biologics (tumor necrosis factor antagonists). In this paper we present a case of a 59 year old man with AOSD treated with adalimumab, diagnosed with granulocellulare tumor of the skin in the course of therapy with the TNF antagonist.