Following his departure from Nightline Koppel formed a three-year partnership with Discovery Communications as managing editor of the Discovery Channel. While at Discovery Koppel produced several lengthy documentaries on a variety of subjects including a 2008 four-hour miniseries on China, which Koppel "ranks with some of the work that [he is] most proud of over the years." The four-part documentary, called The People's Republic of Capitalism, is an extensive look at the fast-changing country. It takes a look at the role of Chinese consumers in the growing -but yet communist- economy.
Koppel and Discovery Communications parted ways in November, 2008.