Résumé : In a French -Belgian collaborative study the incidence of coronary heart disease (CHD) in 2699 middle-aged males was related to the type A behaviour pattern assessed by means of the Bortner scale, which had been validated against the structured interview of Rosenman and Friedman in the Belgian subgroup. The relative risks of the fourth to the first quartile of the Bortner Scale were 1.70, 1.64 and 1.84 for total CHD, hard and soft events, respectively. The relationships of type A behaviour to CHD was independent of age, smoking, systolic blood pressure, serum cholesterol, body build and socio-professional status.