Experimental studies suggest that cytokine production may be triggered by seizure activity. Here we determined the levels of interleukin-6 (IL-6) and its soluble receptor components (sIL-6R and sGp130) in CSF and serum from control subjects and patients after different types of seizures. IL-6 levels were increased after seizures, whereas sIL-6R levels were decreased. Interestingly, the levels of IL-6 were strongly increased after recurrent generalized tonic-clonic seizures (GTCS), whereas after single tonic-clonic or prolonged partial seizures IL-6 levels were increased to lesser extent. These results provide further support for a hypothesis of cytokine production induced by seizure activity per se.