Introduction: The commonly found developmental cysts are the dentigerous cysts of the maxilla and mandible, which are often related to impacted third molar teeth in the mandible and impacted canines. Bilateral dentigerous cysts are rare and occur typically in association with a developmental syndrome or systemic diseases such as mucopolysaccharidosis and cleidocranial dysplasia. Case Presentation: The following is a report of management of a case of unusual bilateral, non-syndromic dentigerous cysts associated with right mandibular canine and first premolars and left mandibular canine and both premolars. The most unusual aspect of the case was that contrary to the radiologic appearance of a developmental dentigerous cyst and with permanent teeth impacted and deciduous teeth present in the oral cavity, histopathologic examination on the right side revealed an aggressive follicular odontogenic keratocyst which was mimicking a dentigerous cyst. The case had a long term follow up of 10 years. Conclusions: This case report strongly emphasizes the importance of the fact that the final diagnosis of an odontogenic cyst requires proper clinical, radiographic and histopathological coordination as was seen in the above case, failing which a diagnostic dilemma arises.