Dentigerous cysts are odontogenic cysts that form on the crown of an unerupted or partially erupted tooth. They are specifically anchored to the cementoenamel junction. Dentigerous cysts are known to rarely involve impacted deciduous teeth. Because of this rarity, this article reports a unique case of a five-year-old female patient who developed a dentigerous cyst in relation to a developing permanent left mandibular first molar tooth with its surgical treatment and histopathological features.