Based on a series of eight personal cases and a review of the literature, this study tries to define the diagnostic elements of aseptic osteomyelitis. Although sternocostoclavicular sites are immediately suggestive of the diagnosis, lesions of the pelvis and spine and long bones of the limbs are particularly difficult to diagnose. Inflammatory type pain occurred in episodesover a number of years and responded to NSAIs and possibly diphosphonates. Laboratory abnormalities were usually confined to a raised ESR, but alterations of the IgA levels, similar to those observed in ankylosing spondylitis were observed in four cases. Hyperostosis occurred late in the course, preceded by signs of osteomyelitis, periosteitis or enthesitis. Histology does not provide any formal conclusions. The most suggestive lesions are those of nonspecific aseptic osteomyelitis, followed by a Paget-like appearance. The interpretation of these findings may be complicated by the presence of eosinophils, giant cells or mast cells. Two elements are very valuable for establishing the diagnosis: the presence of infraradiological anterior thoracic increased uptake on bone scan and the presence of a skin disorder, either severe acne or, more especially, palmoplantar pustulosis.