Dentigerous Cyst/developmental cyst of benign odontogenic origin are ones that surround the crown of impacted, embedded, unerupted or developing teeth. Dentigerous cyst is second most common cyst of the oral cavity after radicular cyst. They are usually solitary in occurrence and mostly associated with the mandibular third molars. Dentigerous cysts involving impacted second premolars are rarely reported in the literatures. We present a rare case of dentigerous cyst in a 12-year-old female patient associated with an impacted mandibular second premolar. How to cite this article: Mishra R, Tripathi AM, Rathore M. Dentigerous Cyst associated with Horizontally Impacted Mandibular Second Premolar. Int J Clin Pediatr Dent 2014;7(1): 54-57.