Rubinstein-Taybi syndrome (RTS) is a rare genetic developmental disorder that often shows associated language delay. However, literature on language development in RTS is very limited, particularly for the period of early communicative development, when standardized testing can be minimally informative. The purpose of the current study was to present a descriptive profile of the intentional communicative acts of a 4-year-old child with RTS, both to add to the literature on the syndrome, and as an example of non-standard profiling of early communication. The child was video-recorded in a natural context with familiar conversational partners. Analyses of the videotaped interactions included rate of communication, communicative functions and modes, and discourse patterns in terms of initiation and response. The child's mean rate of communication was 6 communicative acts per minute. In terms of communicative function, assertive (commenting) communicative acts were most common, followed by directive (requests) and expressive (affective) acts. Mode of communication was less advanced than communicative function; vocalizations were the most frequent mode, although linguistic skills were emerging (signs, single words). Implications for treatment are suggested for children with development delays on the threshold between prelinguistic and one-word phases of development. (Contains 5 tables and 3 footnotes.)