Selected at random from a special consultation in a general teaching hospital in the City of La Habana, 10 epileptic patients were studied. They were clinically, as well as electroencephalographically diagnosed; followed by treatment with different anticonvulsant drugs for a period not less than 3 months and not greater than 5 years. 100 metaphases of each one of the patients were analyzed without finding any deviation in the normal diploidy number of chromosomes (2n = 46), nor alterations in the morphology of the same. We consider this work a preliminary report which does not permit us to arrive at definite conclusions at this moment; but in subsequent work, which we are already carrying out, we hope to issue some considerations with respect to the use of anticonvulsant drugs and their effects in the human chromosomes.