BackgroundKissing molars (KMs) is defined as a state in which the apex of two impacted molars face opposite directions and the occlusal surfaces touch each other and the crown is in one follicle. Class III KMs have been reported previously; however, reports on class III KMs in young people (< 18 years of age) are limited.Case presentationHere, we present the case of KMs class III confirmed at an early age, supported by a review of the literature. The patient was a 16-year-old female and experienced discomfort in the left molar of the lower jaw and visited in our department. We diagnosed KMs based on an impacted teeth on the buccal side, near the lower jaw wisdom teeth, and a cyst-like low-density area observed around the crown of both teeth, as revealed by computed tomography. We decide to extract the tooth and enucleate the cyst under local anesthesia as the patient experienced discomfort due to occlusion. Furthermore, the cyst-like structure removal and tooth extraction including tooth root were necessary as the patient had KM class III, possibly inducing complicated malocclusion. Although no previous reports recommended timing for KMs tooth extraction, we propose that extraction at an early stage is important regardless of age especially in class III cases.ConclusionsWe report a case of KM class III detected at an early age.