Hydrogen peroxide (H₂O₂) is a colourless and odourless liquid with oxidant characteristics used for various purposes. Like other caustic substances, direct injuries may develop if H₂O₂ is swallowed and systemic air embolisms, Oedema and irritation may occur due to the resultant gaseous oxygen. This study discusses a patient who was detected with the presence of accidental injection of insulin syringe filled with 60 units of 30% hydrogen peroxide instead of insulin. As there is no specific antidote was available, the patient was provided with conservative management for the clinical conditions.