Children gradually develop interpretive theory of mind (iToM)--the understanding that different people may interpret identical events or stimuli differently. The present study tested whether more advanced iToM underlies children's recognition that map symbols' meanings must be communicated to others when symbols are iconic (resemble their referents). Children (6-9 years; N = 80) made maps using either iconic or abstract symbols. After accounting for age, intelligence, vocabulary, and memory, iToM predicted children's success in communicating symbols' meaning to a naive map-user when mapping tasks involved iconic (but not abstract) symbols. Findings suggest children's growing appreciation of alternative representations and of the intentional assignment of meaning, and support the contention that ToM progresses beyond mastery of false belief.