The ratio of γ-glutamyl transferase to HDL-C (GGT/HDL-C) has been proposed as a discriminator of metabolic syndrome. The purpose of this study was to elucidate the relationship between GGT/HDL-C and glycemic status in women. The subjects were 18,218 middle-aged women who had received annual health checkups in their workplaces. They were divided by habitual alcohol intake into nondrinkers, occasional drinkers, regular light drinkers, and regular heavy drinkers. In overall subjects, hemoglobin A1c level and prevalence of diabetes tended to be higher in subjects with higher GGT/HDL-C, and GGT/HDL-C tended to be higher with an increase of alcohol intake. The odds ratio for hyperglycemia in subjects with vs. subjects without high GGT/HDL-C tended to be lower with an increase of alcohol intake, and the association between high GGT/HDL-C and hyperglycemia was significantly weaker in regular heavy drinkers than in nondrinkers. In middle-aged women, there were positive associations of GGT/HDL-C with alcohol intake and glycemic status, and the association between GGT/HDL-C and glycemic status tended to be weaker with an increase of alcohol intake. Thus, alcohol use should be taken into account when GGT/HDL-C is used as a discriminator of diabetes.