Jacek Saryusz-Wolski was nominated the first Polish plenipotentiary for European integration and foreign aids (pełnomocnik ds. integracji europejskiej i pomocy zagranicznej) when this office was created in 1991 by the prime minister Jan Krzysztof Bielecki. Jacek Saryusz-Wolski held this position till 1996, despite the frequent government changes. He returned to the government in 2000, when the prime minister Jerzy Buzek has nominated him a secretary in the European Integration Committee (Komitet Integracji Europejskiej). Jacek Saryusz-Wolski played an extremely important role in the negotiations in Nice in 2000.
He was elected an MEP, on 13 June 2004, as a candidate of Civic Platform, in the constituency #6 (Łódź Voivodship) receiving 66,589 votes (that is 16,92%, the best result in the region). On 20 July 2004 he was elected a Vice President of the European Parliament, and was at the position till 16 January 2007.