The authors report on a case of spondyloepiphyseal dysplasia tarda (SDT). The most important clinical and radiological signs are described and the criteria for differential diagnosis listed. Among the bone dysplasias Maroteaux, Lamy and Bernhard distinguished in 1957 a discrete form which they called spondyloepiphyseal dysplasia tarda. The condition was found in 20 patients from four generations of three families studied. SDT is a rare and little-known abnormality of bone development. There have been very few communications concerning this condition. Furthermore, this very rare condition is not considered often enough in differential diagnosis and the findings are often misinterpreted; this also occurred in earlier examinations of the case reported here. As early as 1937, Volhard et al. saw a clinical picture corresponding to this condition in three brothers, but they did not take the malformation to be an autonomous disease; they merely stated that the clinical picture differed from that of Morquio's disease. Giedeon et al. classified the changes found in their patients as being associated with Morquio-Brailsford dysostosis.