Summary: It is known that, there exists insufficiency in humoral and cellular immune systems of epileptic patients. Furthermore there is an opinion that antiepileptic treatment decreases the serum immunoglobulin level in the epileptic patients. Our aim was to study the effect of anti-convulsive therapy in the patients subject to chronic antiepileptic treatment, on Ig levels of patients serum, and also to find out if it has caused immune system dysfunction. The serum immunoglobulin levels of 43 patients in ages between 1.5 and 49 years old (average: 18.97 years) have been studied by use of immunodiffusion method. Twentyfive patients were taking carbamazepin, 9 patients valproic acid, 6 patients phenytoin, 8 patients phenobarbital and its derivatives respectively. It was found out that IgA and IgM levels in 26 patients were low. IgA levels of 12 cases (46 %) IgM levels of JO cases (38.5 %), and IgA levels of 4 cases (15.4 %) were low in 26 patients. It was found out that Ig levels of patients were considerably low when compared to control group (p<0.001 for IgA, p<0.01 for IgM). The cases were analysed in terms of age, sex, epilepsy type and the drug type used. The relation between these parameters and Ig levels were discussed in comparasion with literature.