Mucopyoceles are rare lesions defined as infected mucoceles. They have been reported only in the paranasal sinuses and appendix. Our case is the first to be reported in the oral region. A 58- year-old male presented with complaint of a painless swelling of two years duration in the right buccal sulcus with associated pus discharge. Radiographic examination ruled out pulpal and periodontal foci of infection and histopathology confirmed an underlying mucopyocele in the right buccal mucosa.