The influence of levetiracetam (LEV) and valproic acid (VPA) monotherapy on sex-steroid hormone profile was investigated in thirty prepubertal children. VPA-treated children showed greatest androstendione concentrations when compared to LEV treated children (p=0.016) and to controls (p=0.011). All other reproductive endocrine hormones were similar among groups. In conclusion, LEV does not seem to induce changes in reproductive endocrine functions as well as clinically relevant endocrine side effects in prepubertal children.