The attributions made by Chinese immigrant (n=28) and Euro-Canadian (n=27) mothers of 5- to 9-year-old boys regarding the causes of child prosocial and problem behaviors exhibited by children with and without attention-deficit/hyperactivity disorder (ADHD) were investigated. Mothers’ attributions were elicited using audio-taped scenarios of child behavior. In one-half of the scenarios, the child was described as having ADHD. All mothers attributed less responsibility to the child or to the parent for problem behaviors when the child was described as having ADHD than when the child was described as not having a behavior disorder. Mothers also attributed prosocial child behaviors and the behavior of children without ADHD more to parental factors. In comparison to Euro-Canadian mothers, Chinese immigrant mothers saw children as less responsible for prosocial behavior. Mothers also completed a measure of beliefs about ADHD. Although there were some subtle cultural differences in these beliefs, mothers from both cultural groups endorsed generally accurate beliefs about ADHD. Implications for understanding the cultural uniqueness and similarities of maternal attitudes regarding child behavior and ADHD are discussed.