A literature review was conducted to describe important concepts involved in functional analysis of verbal behavior as well as to evaluate empirical research findings on acquisition of picture exchange-based vs. signed mands to suggest instructional implications for teachers and therapists to teach functional communication skills to children with autism. Research findings indicate that children with autism acquire picture exchange responses to mand for reinforcing items more easily and rapidly than signed responses. There is also a strong relation between motor imitation, matching skills and sign language acquisition. It is suggested that both motor imitation and matching skills be examined to teach manual signs to children with autism. Speech is the most common response form, but writing, typing, signs, pictures, gestures, or eye gaze should also be considered for manding. A decision making process is proposed to determine a proper communicative form considering abilities and environmental conditions of a child concerned.