Abstract: A GPS golf diagnostic system for receiving radio signals from earth orbiting GPS satellites, determining the latitudinal, longitudinal and altitudinal coordinates of the diagnostic system, and computing the distance between these coordinates and a plurality of known positions is disclosed. The diagnostic system of the present invention utilizes the computed data for informing the user of the distance between the present position of the golf ball and known positions such as previous ball position, green location and pin position. The diagnostic system is further useful for keeping track of shot distances, clubs used, scores obtained on each hole and total game scores for a plurality of courses.