A supercharger lubricating structure for an internal combustion engine is provided that can supply oil to a supercharger through a short oil passage without use of external piping and downsize a lubricating oil pump. A supercharger lubricating structure for an internal combustion engine can be characterized by the following: A rotating shaft can be connected to a crankshaft via a joint. A connection pipe can be insertably passed through the crankshaft and the rotating shaft to allow an intra-crankshaft oil-feed passage and an intra-rotating-shaft oil-feed passage to communicate with each other. An eccentric shaft portion can be provided on the rotating shaft. A supercharger composed of an orbiting movable scroll and front and rear fixed scrolls can be provided on the eccentric shaft portion via needle bearings. The front and rear fixed scrolls can be provided with ball bearings and the needle bearing supporting the rotating shaft. Oil passages can be disposed to allow the intra-rotating-shaft oil-feed passage, the ball bearing, the needle bearing and the needle bearings to communicate with one another.