Weakness in Germany and China also pressured sales that analysts said were worse than expected throughout the world, and shares of the world's largest hamburger chain fell 1.9 percent.
Sales at U.S. restaurants open at least 13 months fell 0.6 percent, the latest sign that the fast-food sector that had performed well through most of the recession is weakening.
The decline in U.S. sales at stores open at least 13 months was McDonald's second straight monthly decline and comes less than a week after rival fast-food chain operator Yum Brands Inc (YUM.N) forecast weaker-than-expected fourth-quarter sales.
"It does not bode well for spending in the (U.S.) restaurant category,"said Tom Forte, an analyst at Telsey Advisory Group. He added that high unemployment among 18- to 34-year-olds is weighing on the fast-food industry that McDonald's dominates.
But analysts did note that McDonald's sales were hurt by having one less Saturday and one more Monday in the month than in 2008. The company typically does more business on the weekend.