Stelmachowski was a member of Armia Krajowa, the Polish resistance during Second World War.

He also served as Marshal of the Senate (1989–1991), Minister of Education (1991–1992), and presidential advisor from (2007–2009).

In his advisory capacity he suggested doing away with the secrecy of the Union of Solidarity; his idea was to "break away" and "create open structures as much as possible".

[1] Stelmachowski was the founder and then president of Stowarzyszenie "Wspólnota Polska", serving until 11 May 2008.

The Polish President Lech Kaczynski expressed his condolences to family and friends as did politicians from across the political spectrum in Poland, representatives of Polish emigrant organizations in Belarus, Lithuania and United States.