The mandibular buccal bifurcation cyst is a cystic lesion occurring on the buccal surface of the permanent mandibular first molar in 6- to 8-year-old children. The purpose of this article was to present a case report of an 8-year-old with a radiolucent area on the permanent mandibular left first molar, with clinical, radiological, and histological characteristics compatible with the pathological entity mentioned. The treatment adopted in this case was enucleation without extraction. The patient is still under observation without any sign of recurrence.