After one patient had shown rachitic bone changes and analogous chemical deviations in the blood after long-term antiepileptic treatment, 51 children were examined. They had undergone anti-convulsive treatment at least for 3 years. X-rays of the skull, knee, hand-joints and determinations of serum calcium, phosphate and alkaline phosphatase have been carried out. Another case of rickets could not be found. 13 patients (25.5 %) have shown ossification disturbances consisting in increased number and intensity of transverse lines of the metaphyses. These 13 patients had had more severe cerebral damage than those without pathological X-ray findings. They had received higher doses and always a combination of at least 2 preparations. Biochemical alterations, however, could not be found in any case. The ''antiepileptic rickets'' disappeared after vitamin D administration, after which the child''s state became much better.