Antiepileptic drugs (AE) have been held to be responsible for sexual dysfunction in epileptic patients. They might also be responsible in that aspect by leading autonomic neuropathy. In the present study, relationship between autonomic neuropathy, sex hormone levels and sexual dysfunctions were investigated in patients treated by AE drugs. Included into the study were 35 patients (24 men, 11 women) who have been receiving one of three AE drugs (phenytoin, carbamazepine or valproate) at least for two months, and 22 control cases (16 men, 6 women). In both groups SSR, RRIV were measured and serum levels of sex hormone binding globulin (SHBG), prolactine, luteinizing hormone, follicle stimulating hormone, estrodiol, progesterone, total and free testosterone were determined. In patients receiving AE drugs motor and sensory nerve conduction velocities were significantly slower than controls. Sympathical nerve fibers were not affected in regard to autonomic study findings. However, it was compatible with parasympathetic affection in patient group (more prominent in patients with sexual dysfunction). On the other hand, serum level of free testosterone was lower, total testosterone and SHBG were significantly higher in patients as compared to the control cases. It was concluded that parasympathetic affection might play a role, along with the other factors, in sexual dysfunction of patients, treated with AE drugs.