Fipronil is a broad-spectrum phenylpyrazole insecticide almost used to protect corps from insects but also to treat lice and ticks in chickens. The U.S. EPA classified fipronil as Group C, possible human carcinogen, therefore International organizations defined admissible limits for the fipronil usage which in egg is of 5 µg/L4. LC-MS/MS technology can provide a robust and reliable method to detect such a contaminant in food.