BACKGROUND AND OBJECTIVE: Coffee is a major caffeine-containing food source that can be used for treatment of apnea in prematurity. However, few studies have examined the association between coffee consumption and sleep-disordered breathing (SDB). We investigated whether coffee consumption is associated with the oxygen desaturation index (ODI) as a marker of SDB among middle-aged Japanese male workers. METHODS: The subjects were 1126 male local government workers aged 22-59 who participated in SDB screening in 2011-2012. Daily coffee consumption was assessed by a self-administered questionnaire. We measured 3% oxygen desaturation (3%ODI) during a night's sleep using a pulse oximeter. A general linear model was used to calculate the multivariate-adjusted means of 3%ODI per quartile of coffee consumption. We further analyzed the data after stratifying by overweight and current smoking status. RESULTS: A inverse association between coffee consumption and 3%ODI was found. The multivariate-adjusted mean of 3%ODI for the lowest and highest coffee consumption groups were 11.9 times/h and 10.6 times/h (p for trend = 0.06), respectively; 14.6 and 11.5 times/h (p for trend = 0.01) in overweight participants; and 12.7 and 11.0 times/h (p for trend = 0.06) in non-smokers. No associations were found in non-overweight and smoking workers. CONCLUSIONS: Our results suggest that higher coffee consumption was associated with lower 3% ODI as a marker of SDB in overweight and non-smoking workers.