Sonographic assessment of the skeleton is a routine part of fetal anomaly scanning. We report a series of 35 cases seen during a 7‐year interval in which a skeletal dysplasia was suspected prenatally. In 7 (20 per cent) of the 35 cases, a specific diagnosis could not be made either pre‐ or postnatally. Follow‐up was incomplete in one case. In 32 (91 per cent) of the 35 cases, prenatal sonographic examination correctly predicted the prognosis, although in only 11 (31 per cent) of the 35 cases was the suggested prenatal diagnosis proven to be correct. The difficulty of making an accurate prenatal sonographic diagnosis in fetuses with suspected skeletal dysplasias throughout gestation, especially in the third trimester, and the importance of comprehensive multidisciplinary postnatal assessment in these cases are emphasized. © 1998 John Wiley & Sons, Ltd.