The company reported delivering just 26 aircraft in September, down from 87 it delivered in the same month a year ago.
For the quarter, the company delivered 63 aircraft, bringing its nine-months deliveries total to 302 aircraft.
Year-to-date net orders were down 84 from a year earlier, while net orders for the 737 MAX fell by 184.
Boeing had been the world's largest aircraft maker, but the 737 MAX fallout has allowed European rival Airbus (EADSY) to take the No. 1 spot. The 302 aircraft delivered by Boeing pales in comparison to the 571 aircraft delivered by Airbus so far in 2019.