Kaczyński was the President of the Supreme Chamber of Control (Najwyższa Izba Kontroli, NIK) from February 1992 to May 1995 and later Minister of Justice and Attorney General in Jerzy Buzek's government from June 2000 until his dismissal in July 2001.
In 2001 he founded the political party Law and Justice (Prawo i Sprawiedliwość - PiS), usually labelled 'conservative' by media, with his brother Jarosław.