We report 15 patients encountered over 13 years who presented with inflammation of subcutaneous fat and were given clinical and pathologic diagnoses of Weber--Christian disease (WCD). Prominent clinical features included female predominance, lower extremity nodules, fevers, arthritis/arthralgias, and myalgias. Notable laboratory features were elevated erythrocyte sedimentation rate, anemia, leukopenia, and hypocomplementemia, frequently with circulating 7S IgM or immune complexes at times of active symptoms. Histologic findings were lobular--together with frequent septal--panniculitis, fat-laden macrophages, variable cellular infiltrates, necrosis, and occasional vasculitis. Follow-up revealed the death of 2 patients and disease stabilization or improvement in 13 patients. Six patients developed features of other diseases (factitial disease, erythema nodosum, acute myelogenous leukemia, rheumatoid arthritis, systemic lupus erythematosus, and sarcoid) and a seventh may have had erythema induratum. We suggest that classic WCD, as originally described, reflects an increasingly recognized spectrum of panniculitides. These are syndromes of diverse etiology that share many clinical, inflammatory, and immunologic features.