He was also a lecturer at Harvard University and the founder of the Research Institute for Market Economy in Gdańsk (Instytut Badań nad Gospodarką Rynkową w Gdańsku).

He is an author of a book on famous liberals and he also writes short articles for several newspapers and magazines, including Rzeczpospolita, Gazeta Wyborcza, Parkiet, Polityka, Wprost and Newsweek.

His major successes were the foundation of the Warsaw Stock Exchange and the mass privatization programme (Program Powszechnej Prywatyzacji).

In the 2004 European Parliament election he was a candidate of Civic Platform in constituency #1 Pomeranian Voivodship and received 79,879 votes (=20.17%, the best result in the region).

Lewandowski has expressed skepticism about the scientific consensus on anthropogenic climate change, putting him at odds with many of his colleagues in the Barroso Commission.