The nomination of Mr Cimoszewicz, which was almost certain to be accepted by President Aleksander Kwasniewski, marked the end of a week of hard bargaining between leaders of the former Communist Social Democratic Alliance (SLD) and its junior coalition partner, the Polish Peasants' Party (PSL). It appeared to guarantee that Poland will continue moving in the direction of economic reform, and preparing itself for membership of the European Union and Nato.
Mr Cimoszewicz, a 45-year-old lawyer and former justice minister, was one of several candidates for the premiership following Mr Oleksy's dramatic resignation last week amidst protestations of innocence. Although he is part of the SLD's parliamentary caucus, he is not a member of its core party, and is seen as something of an independent spirit. As justice minister he became famous for his "clean hands" campaign aimed at ensuring that government officials were not using their positions to reap illicit financial gains - a policy which antagonised large sections of the SLD itself.
Mr Cimoszewicz also made his mark on the national level when he ran unsuccessfully against Lech Walesa in the 1990 presidential election.
The PSL originally proposed its own candidate for prime minister, but finally agreed to the candidacy of Mr Cimoszewicz yesterday while making it clear that it expected to be given more ministries in the new government.
Although Poland's constitution allows 14 days for the appointment of a new prime minister following a resignation, many of the country's senior leaders - including Mr Kwasniewski - had pressed for earlier agreement on a replacement. Mr Kwasniewski, who today flies to Switzerland to participate in a meeting of the World Economic Forum, feared wrangling over Mr Oleksy's successor could have created an impression of instability.