The purpose of this study was to examine whether anxious shyness and regulated shyness, initially identified in the Chinese culture, is found in South Korean children, and to explore whether these two forms of shyness were differentially related to children's psychosocial functioning. Participants were 544 fourth to sixth grade children (251 girls, M age = 11.38 years old) who were recruited from an elementary school in Bucheon City, South Korea. Children's anxious and regulated shyness were measured using peers' nominations and teachers' ratings, whereas their social preference and social impact were assessed using peers' nominations. Parents rated their children's temperamental shyness and effortful control, and children self-reported their loneliness and interpersonal concerns. The results of confirmatory factor analysis replicated the two factor model of shyness found in previous studies of Chinese children. Anxious shyness and regulated shyness were positively associated and were similarly related to temperamental shyness. Anxious shyness was negatively related to effortful control and social preference, and positively associated with self-reported loneliness and interpersonal concerns, whereas regulated shyness was positively related to effortful control and social preference and negatively associated with loneliness and social impact. These results were generally consistent with prior Chinese findings and provided preliminary support for the construct validity of anxious and regulated shyness in another Asian culture that emphasizes interdependence and modesty. Copyright © 2013 John Wiley & Sons, Ltd.