The prevalence and sociodemographic variance of Type A behavior was studied among 1,721 preadolescents, adolescents, and young adults in Finland. The AFMS questionnaire (Type A behavior questionnaire for the Finnish Multicenter Study), as self-rated and assessed by mothers, and the Hunter-Wolf A-B Rating Scale (HWolf) were used. There was considerable variation between measures: On the AFMS boys scored higher, whereas on the Hwolf girls scored higher. In contrast to earlier findings, Type A behavior was more prevalent among rural subjects than among urban subjects. Economic and occupational status of the family were of no importance. The notion that the Type A behavior pattern characterizes urban, middle-to upper-class males was not validated in this group of Finnish children and young adults.