The capacity to tell a joke is a highly complex interpersonal event that depends upon the maturation of certain developmental achievements which are absent or stunted in children with Asperger's Syndrome. These include the ability to know another's mind, a sense of interpersonal timing and, most notably, a capacity for abstract thinking. The author discusses Freud's (1905) notion of joke-work, which is akin to dream-work, both of which are pathways to forming mental representations. Freud considered joke-work as a mental activity that operated on the verbal level and the author examines the preverbal dimensions that are rooted in the earliest mother/infant interactions. An extended case discussion of the psychoanalytic treatment of an Asperger's boy is offered to illustrate these points and to demonstrate the activity of joke-work as a means of building mental representations.