Before the age of 14 years, 1% of the paediatric population will develop a seizure. The only systematically required complementary examination is an electroencephalogram (EEG). Additional biological or radiological examinations depend on the circumstances, the past medical history of the patient and other associated symptoms or clinical signs. A seizure can be the first sign of acute intoxication and represents a severity criterion. Failure to detect the toxic cause of a seizure can lead to a delay in the access or administration of an antidote if applicable. This can lead to target organ toxicity due to the absence of specific treatment. In the current French guidelines for a first seizure, a toxicological analysis is recommended if there is a possibility of exposure to toxic medications or products. However, this screening is often missing, unless a witness suggests that the child may have been exposed to a toxin.The recognition of a paediatric toxidrome is low among paediatricians, paediatric neurologists or emergency physicians. Since the end of the 90s, the molecules usually incriminated with seizure onset after intoxication are: with a high risk (polycyclic antidepressant, theophylline, isoniazid); intermediate risk (fluoroquinolones, tramadol, lidocaine, lithium, anticonvulsive medications) and low risk (selective serotonin reuptake inhibitors). Among infants, the molecules are quite different mainly because of the unintentional or malicious aspect of the intoxication and are dominated by sympathomimetic agents, antihistamine drugs, anticholinergic molecules, antidepressants and muscle relaxants. New drugs have been associated with seizures in young intoxicated children like bupropion, tramadol and venlafaxine. These agents are not detected by usual toxic analysis.