This article reports a case of febrile, symmetrical and painful soft tissue swelling on both thighs in a 54-year-old otherwise healthy male patient. Histologically, necrotizing panniculitis of subcutaneous adipose tissue was described as a marker manifestation of a previously unknown alpha-1-antitrypsin (A1AT) deficiency with pulmonary emphysema and low plasma A1AT levels. The PiZZ homozygous form of A1AT could be diagnosed by gene sequencing. Complete remission of panniculitis could be achieved by A1AT replacement therapy.