Gelsemium intoxication remain rarely reported especially in a pediatric population. The phytochemical composition of Gelsemium indicates that numerous toxic indole or oxindole alkaloids are found in different tissues of the plant. In this study, we reported the case of a three-year-old boy intoxicated to Gelsemium specie. He was admitted for lower limb stiffness which has been spontaneously resolved in 48hours. A toxicological screening based on a targeted and an untargeted approach using liquid chromatography hyphenated to high resolution tandem mass spectrometry has been performed on urine sample of the child. It allowed to identify gelsemine, as well as gelsedine and its hydroxylated metabolites, which are toxic alkaloids encountered in Gelsemium specie. Furthermore, gelsemine was quantified in the urine sample at a concentration of 40ng/mL. Even if Gelsemium poisoning remain a rare cause of intoxication, inclusion of specific alkaloids in targeted screening may be relevant to identify such an intoxication. Furthermore, untargeted screening may be regarded as a complementary approach to investigate additional chemicals related to a dedicated intoxication, useful to support the diagnosis.