Seven children who had partial arrest of the growth plate after neonatal arterial cannulation, developed obvious skeletal changes in adolescence. Cannulation of the femoral artery produced ischaemia which led to four cases of ipsilateral shortening of the lower limb and one of partial arrest of the proximal femoral physis with subsequent coxa valga. The two arrests in the upper limb affected the humerus, ulna and radius, and the radius alone, after cannulation of the brachial and radial arteries, respectively. These late effects of cannulation are not widely appreciated, and may occur as a result of thrombosis rather than extravasation. Arrest of the growth plate (physis) may complicate arterial cannulation during infancy and childhood. The resultant discrepancy or deformity of the limb is not always recognised before skeletal maturity, by which time a relatively simple correction by epiphysiodesis is impossible. We describe seven cases of physeal injury after arterial cannulation in which complications such as perforation of the vessel wall, aneurysm or extravasation were not sustained. Two cases involved the upper limb, producing shortening of the radius principally, but also of the ulna and the humerus. Four cases of femoral and tibial shortening occurred as a result of femoral cannulation. Although there has been debate in the literature about the cause of the resultant leg-length disparity, since an intrinsic mild discrepancy cannot always be ruled out in each of our patients, the ipsilateral leg had developed mild circulatory impairment after the cannulation. The last case involved the lateral portion of the proximal femoral growth plate.