Mucoceles are progressive growths of encapsulated mucus capable of eroding and destroying adjacent bone structures and compressing neighboring organs. They are caused by the presence of mucous cells from the sinus membrane in an undrained space. These mucoceles can become infected, leading to the formation of a mucopyocele. They may manifest many years after the initial trauma to the facial bones, especially those involving the frontal sinuses. The discovery is either fortuitous or secondary to imaging: Computed tomography (CT), magnetic resonance imaging, carried out during an etiological assessment of symptoms such as frontal pain, proptosis, diplopia, nasal obstruction, rhinorrhea. Rarely, purulent discharge through a frontal cutaneous fistula may be the initial sign of a frontal sinus mucocele or mucopyocele. We report a case of mucopyocele of the frontal sinus presenting in the form of purulent discharge at the frontal level following a neglected frontal fracture and present our therapeutic approach.