In 1998 Beijing began an intensified air pollution control program, and over the last 20 years the city has implemented a series of measures including energy infrastructure optimization, coal-fired pollution control, and vehicle emission controls. These efforts successfully reduced air pollution. In the five years from 2013 to 2017, fine particulate pollution (PM2.5) in Beijing fell by 35% and by 25% in surrounding regions. This report outlines how Beijing’s air quality management programme has evolved over the past quarter century and makes recommendations for near, medium, and long-term steps that Beijing can take to maintain its momentum toward clean air. The lessons, policies and actions in this report could also help guide pollution reduction measures in other cities looking to improve air quality.