Grocholewski was created Cardinal-Deacon of San Nicola in Carcere by John Paul II in the consistory of 21 January 2001. Grocholewski automatically lost his curial position on 2 April 2005 upon the death of Pope John Paul. He was confirmed in office by Pope Benedict XVI on 21 April. He was one of the cardinal electors who participated in the 2005 papal conclave that elected Pope Benedict XVI. On 21 February 2011, he opted for the order of Cardinal Priest, with his former diaconal church elevated to the level of cardinalitial title. He participated in the 2013 papal conclave that elected Pope Francis.