A device for positioning a stent in a natural canal after passing through an obstacle at the level of a target organ. The device includes a stent, a pusher tube, and a guide. The guide is configured to push the stent through the lumen of the natural canal, and includes at least one flexible part having a predetermined longitudinal stiffness and a lateral flexibility that allow a reversible deformation from a straight position to a bent position so as to follow the curve of the natural canal under the application of minimal external forces exerted by an operator. The device is particularly adapted to the technical field of urology.