Type A behaviour related to school achievement was studied in 1640 randomly selected 12-, 15-, and 18-year-old subjects. Type A behaviour was both self-assessed by the subjects and evaluated by their mothers. Results indicated that school achievement was not related to the global score of Type A behaviour but correlated with three Type A dimensions, i.e. positively with Responsible Hard-driving and Leadership Competitiveness, and negatively with Aggressive Competitiveness. It has previously been shown that hard-driving correlates with a high level of somatic CHD risk factors, while leadership competition is a protective factor, i.e. it is associated with a low level of somatic CHD risk. So, school achievement differentiated adjusted and maladjusted Type A competitors, but not individuals with high and low somatic CHD risk. The results were manifest for boys and girls and for all age groups. Moreover, it was shown that the results were obtained independently of the methods used.