Most acute patella dislocations can be reduced closely using a spontaneous or simple maneuver, but it may not be possible if accompanied the by anomalies, such as rotation of the patella, osteophyte ridge protruding from the femur, or anatomical variations. This case report outlines irreducible acute patella dislocation with anatomical variations, a notched patella. If the reduction of an acute patella dislocation fails, an additional radiological examination and reduction under general anesthesia may be necessary with the possibility of an anatomical variant in mind.