Generalized tonic-clonic seizures are the most common type of convulsive disorders in children. They are always a sign of an epileptogenic cerebral dysfunction and present either acutely, predominantly as a single event with detectable origin, or chronically, recurring as an epileptic syndrome. In view of the etiology and classification of convulsions it is important to differentiate between primarily and secondarily generalized seizures. This distinction is first of all based on an exact description of the very beginning and of the course of the seizures, on the EEG findings and on any connection between the seizures and a particular time of day. Primarily generalized tonic-clonic seizures with and without associated petit mal seizures are manifestations of an idiopathic epilepsy and are most probably genetically determined, secondarily generalized seizures on the other hand are often signs of a central nervous lesion or of another symptomatic form of epilepsy. Benign idiopathic partial seizures, however, take the from of secondarily generalized convulsions during the morning sleep. Prolonged tonic-clonic seizures of any origin require vigorous treatment with anticonvulsants, if necessary in an intensive care unit. Recurrent seizures are treated with long-term anticonvulsant medication. The first-line treatment is valproic acid or phenobarbitone (or if necessary, a bromide) in primarily generalized seizures and carbamazepine or phenytoin in secondarily generalized convulsions. The recommended duration of this therapy and the risk of recurrence of seizures vary widely with the underlying etiology and the type of epilepsy.