Dentigerous cyst is the 2nd most common odontogenic cyst which is associated with the crown of an unerupted tooth. It is usually found in the 2nd and 3rd decades of life, but the frequency in children till now has been reported in dental literature is low. Dentigerous cysts(DC) has more potential to convert into ameloblastoma, squamous cell carcinoma, and mucoepidermoid carcinoma. Here we report a case of an 8–year–old male patient with dentigerous cyst transforming into unicystic ameloblastoma.