Abstract: A two-part mandibular protrusion splint (1) for preventing at least one of snoring and obstructive sleep apnea. The mandibular protrusion splint (1) comprises both a lower part (2) and an upper part (3) and each part includes a shaping and flexurally rigid tray (2a, 3a) which is open, during use, towards the mandibula and the maxilla. Each tray comprises a thermoplastic filler material (4, 5) which can be shaped in a manner of a dental brace to fit the human maxilla and mandibula. Both the trays comprise one or more fixing knobs (5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b), on the respective outer sides thereof, for fastening to a protrusion holder (9). The protrusion holder (9) is rotatably fastened to a fixing knob (5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b), on each of the mandibular tray and the maxillar tray, for bring the mandibula into an anterior position.