We examined the meaning, assessment, and implications of different forms of social withdrawal in Turkey across two studies. In study 1, semi-structured interviews were conducted with children, mothers, and teachers to identify descriptors of social withdrawal. Shyness and unsociability were confirmed through content analyses, and regulated withdrawal, a new subtype characterized by overregulation of behaviors and suppression of own desires during social interactions, was revealed. Based on these findings, the child social preference scale, an established North American measure of social withdrawal, was revised. In study 2, a confirmatory factor analysis on a sample of 599 9–11-year-old children revealed three distinct forms of social withdrawal. Shyness was related to a wider range of child adjustment difficulties than unsociability and regulated withdrawal, although all forms of withdrawal were associated with child adjustment difficulties, providing support for the importance of children's active involvement in social relationships for their positive development and well-being.