The purpose of the study to compare the following factors pre- and postoperatively --cardiovascular risk factors (abuse of nicotine, obesity, disturbances of fat metabolism, diabetes mellitus, hypertension)--complaints, measured at the daily need of nitrangin, and functional capacity in watt. Apart from this the time of waiting for the operation, the pre- and postoperative medication and the problem of the fitness for work and the calculation of the pension were analysed postoperatively. In the study 61 patients were included, in whom an aortocoronary bypass operation was carried out in the period from 1980 to 1988. Postoperatively, the risk factor abuse of nicotine was reduced by most patients, whereas obesity and disturbances of the fat metabolism practically remained uninfluenced. Postoperatively a permanent need of nitrangin was existing only in exceptional cases. An improvement of the functional capacity could be proved only in about half the patients. This partly explained that only one third of the patients became again fit for work after operation. On the other hand, the long time of waiting for the operation which in most cases included a long preoperative inability to work was also decisive for the great number of calculations of the pension after operation.