Dentigerous cysts are rarer to occur in children compared to adult patients.Non-vital deciduous teeth which are associated with dentigerous cysts of inflammatory origin are mostly found in mixed dentition stage. This case report presents a successful management of a large dentigerous cyst that was associated with a grossly carious primary molar which involved multiple unerupted immature permanent teeth of mandible in a 12 years old patient. The procedure which was used for the management was marsupialization. The follow-up evaluation showed complete healing of the cystic lesion, and spontaneous eruption of the involved permanent teeth. It also resulted in complete resolution of facial asymmetry without any recurrence or complications.