Sales fell 1.8 percent at same-store outlets, a category that includes stores that have been open at least one year.
The last time sales dropped month-to-month was in April 2003, the Los Angeles Times reported Thursday.
McDonald's said sales fell in every sales region around the globe, dropping 2.2 percent in Europe and the United States, and 2.4 percent in Asia, Africa and the Middle East.
Along with a post-election decline in stock markets, McDonald's shares fell 1 percent Thursday morning.
In its most recent quarterly report, McDonald's said profits fell 4 percent from the second quarter to the third after dropping 4.5 percent from the first quarter to the second.