Female infant admitted at 7 months of age for a brief generalised tonic-clonic seizure, without infectious process or associated fever, which recurred with similar characteristics 23 hours after the first episode, while she was admitted. No focal onset of the seizure was observed, with maintained vital signs and a normal subsequent physical and neurological examination. The parents reported no personal history of note, she attended regular health check-ups and her psychomotor and staturo-ponderal development was normal. On admission, a complete blood count, renal and liver function tests, acute phase reactants, brain ultrasound and electroencephalogram were performed, with normal results. Given the observation of a conflictive socio-familial situation, a search for toxins in urine was carried out, which tested positive for cocaine in two successive samples. The first sample yielded a quantified level of cocaine metabolites in urine of 1.7 µg/ml and the second, collected a few hours later, 0.4 µg/ml (our laboratory cut-off point of 0.3 µg/ml), which were negative 48 hours after admission. The father is a regular cannabis smoker, but the family members denied cocaine use at home or in their close social and family environment and pointed to the possibility of contact with environmental smoke in a closed room where they had been for hours before the onset of the seizures. Under surveillance by the assigned social worker since discharge, the patient has not presented again with seizures in the following six months and psychomotor development is proceeding normally.