We describe an 82-year-old woman with an acute panniculitis in the left groin as the first sign of chronic renal brucellosis. She was afebrile and had a large erythematoviolaceous plaque with ulceration and liquefaction of the subcutaneous tissue. Histopathologic study showed a septal and lobular panniculitis with neutrophil infiltration, hemorrhage, and necrosis. Microbiologic cultures of a skin biopsy specimen, blood, and urine were negative. A computed tomography scan showed a left "mastic" kidney with a psoas abscess extending to the left inguinal region. The microbiologic culture of the removed renal mass and the serologic tests established the diagnosis of chronic renal brucellosis. Although the clinical picture of cold abscesses in the inguinal area classically suggests a tuberculosis, brucellosis should be included in the differential diagnosis.