--- - |2 Abstract Using a sample of 99 2‐ to 5‐year‐olds (51 girls, 48 boys), we evaluated whether parent‐reported temperamental shyness was associated with prosocial behaviors with same‐aged peers, and considered parenting (use of elaborative emotion language) and parent and child gender as possible moderators of relations between shyness and prosocial behaviors. Active and passive forms of prosocial behavior were evaluated when children were with familiar and unfamiliar peers. There were no direct associations between shyness and peer prosocial behaviors. Fathers’ emotion elaboration predicted more active prosocial behavior with familiar peers. There were significant moderating effects of parental emotion language, and parent and child gender, on relations between shyness and prosocial behavior. When mothers used more emotion elaboration, less shy children showed more active prosocial behavior toward unfamiliar peers and less passive prosocial behavior with familiar peers. Conversely, when fathers used more emotion elaboration, more shy boys engaged in more active prosocial behaviors with unfamiliar peers. These findings suggest that multiple social and contextual factors influence whether shy children become proactive helpers and sharers. Shy boys may particularly benefit from emotion elaboration from fathers whereas less shy children may be most prepared to benefit from mothers’ emotion language. - Social Development, Volume 27, Issue 4, Page 858-875, November 2018.