This paper describes the degree of similarity between repeated ratings (taken 1 year apart) of overt Type A behaviors in 2 samples totaling 633 children. The measure of overt Type A behaviors was the Matthews Youth Test for Health (MYTH), which was completed by the children's classroom teacher. Results showed that correlations between repeated MYTH ratings approximated .55 and in general increased somewhat with the children's school grade, although correlations between repeated ratings of competitive achievement behaviors of boys residing in an affluent eastern suburb were somewhat lower than above. The degree of similarity across 1 year in children's Type A behaviors is comparable to that found for adult Type A behaviors and for other cardiovascular risk factors in children. The discussion includes a consideration of assumptions underlying research on the origins of Type A behavior and suggests that etiological factors in the development of Type A might profitably be studied in primary school-aged children.