Background: Though it is a widely held belief that caffeinated beverages predispose individuals to arrhythmias, it is not clear whether regular coffee consumption is associated with development of atrial fibrillation (AF). Objective: We examined the association between long-term coffee consumption and development of AF in both habitual and nonhabitual drinkers. Methods: A total of 5,972 men and women, aged 45-84 years and without a history of cardiovascular disease at baseline in the Multi-Ethnic Study of Atherosclerosis (MESA) were followed from 2000 to 2014 for incident AF with baseline coffee consumption assessed in 2000-2002 via a Food Frequency Questionnaire and divided into quartiles of 0 cups/day, intermittent nonhabitual (<0.5 cups/day), ≥0.5 to 1.5 cups/day, and ≥1.5 cups/day. Results: Out of the 828 incident cases of AF, intermittent coffee consumption (>0 to 0.5 cups of daily coffee) was associated with a greater risk of incident AF (HR 1.22, 95% CI 1.01-1.49) relative to 0 cups/day in multivariable Cox proportional hazards models after adjustment for numerous AF risk factors; higher coffee consumption was not associated with AF risk (HR 1.03, 95%CI 0.93-1.14 for ≥0.5 to 1.5 cups/day and 1.05, 95%CI 0.97-1.13 for ≥1.5 cups/day). Conclusions: While there appears to be no dose-response association between habitual coffee intake and AF risk, we found evidence that intermittent, but not habitual, coffee consumption is associated with a modestly increased risk of incident AF that deserves further study.