We previously reported that ingestion of 60 mL of red wine or vodka prior to the ingestion of a pancake significantly inhibited the gastric emptying of the pancake in male subjects, but not in female subjects, and that the retention times of wine and vodka were significantly longer than those of the congener of red wine and mineral water in male subjects, whereas in female subjects the retention times of these four drinks did not differ significantly from one another. We hypothesized that the menstrual cycle may influence the gastric emptying of alcohol beverages. Here, we determined and compared the retention times of vodka and water in the stomach during the luteal phase and the follicular phase. Ten female healthy volunteers were studied. They recorded their basal body temperatures every day, and participated in the following experiments: each volunteer drank mineral water or vodka containing 14% alcohol (60 mL) during the low-temperature (follicular) phase as well as during the high-temperature (luteal) phase. The retention time of vodka was significantly longer than that of mineral water during the follicular phase, but no significant differences between the retention times of the two drinks were observed during the luteal phase. In conclusion, the menstrual cycle influences the gastric emptying rate of alcohol.