A balloon catheter utilizing a perfusion balloon at one end thereof is described. The perfusion balloon has a donut shaped cross section having a central opening formed therethrough. The central opening provides a blood flow passage even when the balloon is fully inflated. When inflated, the perfusion balloon is used to dilate a stenotic region of a blood vessel or heart valve to restore blood flow. After deflation, if the blood vessel collapses, the balloon catheter of the present invention can be reinflated and kept in place while the patient is prepared for surgery. In this manner, acceptable blood flow is provided regardless of the length of time required for surgical preparation. In an alternate embodiment, a one-way valve is formed integrally with the perfusion balloon so that the present invention may be better applied to valvuloplasty. In this application, the balloon is inflated at a stenotic region of a heart valve to expand the valve and restore acceptable blood flow. The one-way valve of the perfusion balloon takes the place of the coronary valve so that normal operation of the heart can be maintained during the valvuloplasty process.