The present invention discloses a safe surgical mouth gag (MG) (30) comprising a substantially planar frame larger than the maximal mouth aperture which is defined by at least two cross members, i.e., a longitudinal maxillary cross member (33) and a mandibular cross member (32) and by at least one rod (29) connecting said maxillary and said mandibular cross members; and modules maneuverably interconnected to the same. Said modules are selected from a tongue blade (50) approximately perpendicular to said frames' plane, which is vertically displaceable with respect to said mandibular cross member; a retaining member (53) within which said tongue blade shaft is slidably displaceable; retraction elements (35) for urging the cheeks away from the oral cavity; abutment members (40) for contacting the upper teeth or upper maxilla; and at least one light auxiliary (101) located adjacent to oral cavity, adapted to illuminate the same effectively.