Abstract: Improved rotating blowout preventer including a stationary housing, a bearing housing and a bearing means assembly and seal assembly for mounting an internally located, rotating sleeve for rotating, sealable movement within the bearing housing. The bearing housing and rotatable sleeve cooperate to provide a circumferential passageway and radial ports to direct outwardly of the bearing housing any fluid which leaks past the seal assembly. The structure of the seal and bearing mountings provide for replacement of the seal without contaminating the bearing.