Abstract: Device for cutting a pipe (1) transporting fluid in order to stop the circulation of the fluid at any point, comprising a casing (2, 3) susceptible of being sealingly mounted on the pipe (1). The casing (2, 3) contains at least one blade (8) which is driven in rotation and feed motions so as to cut off the pipe (1) by sawing it transversely. The blade (8) forms a stop surface to the circulation along the section plane of the saw blade. The device is useful in the cutting of fluid flow in pipes and particularly in the case of accidents such as fires in oil wells.