Abstract: Portable apparatus for training a golfer to putt a ball correctly. The apparatus has guide rails and extensible flexible cords which guide the golfer in swinging the putter along a straight line and hitting the ball along a desired path. The rails are secured to the ground by pins which project from the lower surfaces of the rails. When the device is not in use, the flexible cords are wrapped about the pins, and the rails are brought together with the pins of one rail being received in sockets in the other. The device can be broken down or collapsed into a relatively small package which is easily carried in a golf bag.