When a letter is drawn on the forehead, it is often perceived cutaneously as a mirror reversal of the experimenter‐defined stimulus. The occurrence of this phenomenon was examined in 3‐ and 5‐year‐old deaf and hearing boys using a reliable behavioural technique that did not require verbal instruction. Hearing 3‐ and 5‐year‐olds and deaf 3‐year‐olds showed mirror‐reversal tendencies that were quite consistent with those reported previously in adults and 4‐year‐olds. However, this phenomenon was not observed in deaf 5‐year‐olds. The difference was considered to be related to the fact that deaf 5‐year‐olds were in the process of acquiring a considerable vocabulary in a signed language as their first language. The implications of these findings are discussed with reference to possible explanations of the mirror‐reversal phenomenon and the characteristics of the acquisi