Baby sign language is advocated to improve children's communication development. However, the evidence to support the advantages of baby sign has been inconclusive. A systematic review was undertaken to summarize and appraise the research related to the effectiveness of symbolic gestures for typically developing, hearing infants with hearing parents. Eight electronic databases, reference lists, and websites were searched for relevant studies published from January 1990 to February 2013. Studies were included if they involved typically developing hearing children who were exposed to symbolic gestures before age 36 months. Of 1902 identified citations, 10 reports met the inclusion criteria. This review shows that the effectiveness of baby sign in improving communication development remains unclear. However, no evidence was identified to suggest that using baby sign interferes with typical child development.