Introduction:Frontal sinus mucoceles are the commonest among all paranasal mucoceles. With introduction of functional endoscopic sinus surgery, surgeons prefer endoscopic management of sinus mucoceles, but lesions that appear in the lateral part of the frontal sinus can be difficult to access and often need external approaches.Case Presentation:We described a lateral frontal sinus mucocele with intra-orbital extension, which was successfully managed by endoscopic sinus surgery.Conclusions:Endoscopic sinus surgery is the treatment of choice in most frontal sinus mucoceles including lateral frontal mucoceles.