Work status after aortocoronary bypass surgery was evaluated in 1 320 male patients who were less than 60 years old at the time of their operation. The percentage of working patients is maximal two years after surgery (66.5 p. 100) and decreases gradually (53 p. 100) at five years. This percentage remains lower than the 84 p. 100 and 69 p. 100 which were observed twelve and six months before the operation. Multivariate analyses showed that the length of the period of pre-operative inactivity had a preponderant role in predicting work status after surgery. The second best predictor was the type of work in patients aged 45 or more and the educational level in younger patients. All other variables-duration of illness, functional class, other illness, postoperative complications, marital status, annual income, age-had a lesser role. Variables predictive of continued employment (greater than or equal to 2 ans) after surgery were similar. Univariate analyses on postoperative factors showed a negative correlation between recurrence of angina and return to work. A majority of patients who never returned to work after surgery kept a stable income (65.5 p. 100) and 83 p. 100 of them received financial aid from the government.