PURPOSE: This study was conducted for evaluation of the effects of new antiepileptic drugs on bone mineral density in children with epilepsy. METHODS: The study group consisted of 35 age and gender matched controls and 35 epileptic children taking new antiepileptic drugs: 14 on topiramate, 10 on lamotrigine, and 11 on oxcarbazepine in monotherapy. All patients were treated for more than one year and all were normally ambulatory children. We measured serum levels of calcium, alkaline phosphatase, 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D. BMD was measured by dual-energy X-ray absorptiometry at lumbar spine regions L1-L4. RESULTS: Vitamin D levels of the oxcarbazepine group (25-hydroxyvitamin D: 40.3+/-10.5 ng/mL and 1,25-dihydroxyvitamin D: 57.9+/-15.2 pg/mL) were significantly lower than in controls (44.6+/-11.5 ng/mL, 66.2+/-10.5 pg/mL, P<0.05); however, they did not differ significantly in the topiramate and lamotrigine groups. The bone mineral density value was significantly lower in the oxcarbazepine (L1-L4: 0.73+/-0.11 g/cm2) group, compared with the controls (0.84+/-0.06 g/cm2, P<0.05) or patients taking topiramate or lamotrigine. CONCLUSION: Monitoring of bone metabolism is recommended for patients treated with new antiepileptic drugs, particularly oxcarbazepine.