The current study focuses on the theory of mind and attempts to give insight in the sensitivity of infants to make predictions based on agents’ beliefs and actions. In particular, the experiment involves an eye tracking task performed by 13 infants, babies being approximately 6 months old. The eye-tracker investigated motor activity; it showed whether infants could appropriately predict when someone with the false belief that there is a ball in a box a) will reach the box or b) will not reach the box in order to get the desired object (the ball). The same false scenario was firstly attested to a control group of adults. The study shows that infants make an action prediction which is congruent with an agent’s representation of the world. Hence, the study supports that an infant of 6 months understands an adults’ mental state based on the predictions and the functional consequences of his/her actions.