Nonconvulsive status epilepticus (NCSE) is an epileptic condition lasting >30 min, clinically manifested by an altered mental state and associated with continuous epileptiform activity on the electroencephalogram. NCSE is a common yet still under recognized condition and delay in diagnosis and treatment may be associated with increased mortality as well as cognitive/behavioral consequences. We described an epileptic female patient assuming carbamazepine (900 mg/day) and levetiracetam (3,000 mg/day), seizure free for more than 10 years, who developed NCSE during cefixime treatment, a third-generation cephalosporin compound that along with penicillins is classified within the b-lactam class of antibiotics. In our report we outline the importance and the difficulty to choose secure antibiotic treatment in epileptic patients, we discuss the possible mechanisms by which cephalosporins induce neurotoxicity and the need to stress family components questioning about new drugs assumed. Finally we highlight the value of the EEG recording to diagnose NCSE and treat it adequately and promptly.