A wall climbing toy includes a frame body, a drive shaft, a plurality of spring-loaded release valves, a cam shaft, a drive unit, a left gear train, a shaft extension, a plurality of primary crank arms, a plurality of connecting rods, a plurality of suction cups, and a plurality of air tube units. When each of the spring-loaded release valves is displaced from a seal position to an open position, an air seal formed between a corresponding one of the suction cups and a flat surface is broken. When the drive shaft is driven concurrently with the cam shaft to rotate, the air seals formed between the suction cups and the flat surface are broken alternately so as to permit the connecting rods to be alternately pulled away from a flat surface.