Formaldehyde and its products have been widely used in endodontic procedures as intracanal medicaments. Formocresol has gained popularity in pediatric dentistry as pulpotomy medicament. The very nature of formocresol is to fix the soft tissues when exposed. When using it as a pulpotomy medicament, care should be taken to expose only the pulp tissue for such medicaments. When proper isolation techniques are not employed, such injuries can occur as an extended action of the chemical nature of the substance on unintended parts of the oral mucosa. This article presents and discusses the case of coagulative necrosis of Labial mucosa and its subsequent healing, which compromised on the quality of life of the patient. As a pediatric dentist, the clinician should be aware of hazardous effects formocresol and necessary care and preventive measures like rubber dam isolation should me mandatorily employed while using formocresol.