OBJECTIVE: To investigate the relationship between admission plasma glucose and 30-day mortality after primary isolated coronary artery bypass grafting (CABG) in nondiabetic patients. RESEARCH DESIGN AND METHODS: All nondiabetic patients with admission plasma glucose measurement undergoing primary isolated CABG from 1993 to 1997 were included in this study. RESULTS: In 878 consecutive patients (155 women), overall mortality was 3.4% (95% CI 2.3-4.8). The mortality rate in women (n = 11; 7.1%, 3.6-12.3) was higher than in men (n = 19; 2.6%, 1.6-4.1) (P = 0.01). There was a positive correlation between plasma glucose and 30-day mortality among women only (P = 0.0001). There was a higher mortality rate in the upper two glucose quartiles (11.7%, 5.5-21.0) compared with the lower two quartiles (2.6%, 3.0-8.9) in the female patients (P = 0.03); a plasma glucose of 6.0 mmol/l separated high- and low-mortality groups. Furthermore, women in the upper two glucose quartiles had a fourfold higher mortality rate than men in the similar quartiles (P = 0.002). Among men, there was no difference in mortality rate across glucose quartiles. In a multivariate analysis, admission plasma glucose, history of thyroid disease, left ventricular ejection fraction <0.35, operation bypass time, and perioperative myocardial infarction were independently associated with mortality. CONCLUSIONS: Women with admission plasma glucose < or =6.0 mmol/l and men across the whole range of glucose values had similar mortality rates after CABG. The surplus female mortality was found only in subjects with plasma glucose >6 mmol/l. Further studies are needed to appraise the possible influence of glucose status on outcome from CABG in nondiabetic subjects.