Ideomotor theory considers bidirectional action–effect associations to be the fundamental building blocks for intentional action. The present study employed a novel pupillometric and oculomotor paradigm to study developmental changes in the role of action-effects in the acquisition of voluntary action. Our findings suggest that both 7- and 12-month-olds (and adults) can use acquired action–effect bindings to predict action outcomes but only 12-month-olds (and adults) showed evidence for employing action-effects to select actions. This dissociation supports the idea that infants acquire action–effect knowledge before they have developed the cognitive machinery necessary to make use of that knowledge to perform intentional actions.