The panniculitides are a group of heterogeneous inflammatory diseases involving the subcutaneous fat. Traditionally, the clinical and the histopathological study of the panniculitides have been considered one of the most difficult subjects in dermatology. The reasons for this relative unpopularity of the panniculitides are varied. The purpose of this issue of Dermatologic Clinics is to present a clinico-pathologic overview of some panniculitides. Emphasis will be placed on the characteristic histopathologic features for specific diagnosis, and will include short comments about the treatment for each entity.