After eight years in opposition, the Law and Justice (PiS) led by Mr. Jaroslaw Kaczynski returned to power, winning an outright majority in both the 460-member Sejm and the 100-member Senate. The PiS, which endorsed Ms. Beata Szydlo as its premiership candidate, became the first party in the country's post-communist era to win enough seats to govern on its own. Outgoing Prime Minister Ewa Kopacz of the Civic Platform (PO) conceded defeat. On 13 November President Andrzej Duda, a former PiS member, tasked Ms. Szydlo with forming a new government.

The 2015 elections were the first to be held under President Duda who defeated the incumbent President, Bronislaw Komorowski (independent, endorsed by the PO), in the May 2015 presidential elections. Elections took place amid the ongoing migration crisis in Europe. In September, President Duda argued against a German-backed quota system for taking in migrants, saying decisions should remain voluntary at the country level. The government, led by the pro-EU PO, decided to take in 7,000 migrants between 2016 and 2017. During the election campaign, the major opposition parties, including the PiS, spoke out against the decision. Other electoral issues included child care benefits, tax cuts and the retirement age. The PiS promised to repeal the 2012 law that raised the retirement age to 67 and to return the retirement age to 60 for women and 65 for men. It also ruled out adoption of the euro in the near future.

The 2015 elections followed a referendum on 6 September on three issues, including the introduction of single-member constituencies for the Sejm. Although over 78 per cent of voters were in favour of single-member constituencies, only 7.8 per cent of some 30 million eligible voters took part in the referendum. Referendum results in Poland are legally binding only if over 50% of eligible voters take part.