Preoperative predictors of postoperative employment status were studied in 228 patients (aged 25 to 64 years) who underwent cardiac surgery. Of the 150 patients working in the year before surgery, 73% returned within six months. Of those not so employed, 18% started working. Patients who expected preoperatively to return to work did so at an 82% rate compared with 39% of the others. This was a strong predictor in the multiple regression analysis. Educational level and family income were stronger predictors than occupation or level of physical exertion required. Rates of return were higher in patients with less severe angina and less fatigue preoperatively, but did not differ significantly by sex, surgical procedure, or duration of illness. Seven variables predicted work status correctly for 86% of persons. These results suggest that determinants of return to work are largely present before surgery and that patients' attitudes and expectations play an important role.