The figure was in line with a flash estimate issued by the office earlier this month.
Investment decreased by 10.9 percent and domestic demand fell by 9.5 percent in Poland in the second quarter of 2020, the Central Statistical Office reported.
Poland's gross domestic product grew 2 percent in the first quarter of this year, according to a final estimate released by the state-run statistics agency in late May.
The Polish economy expanded by 4.1 percent in 2019 as a whole, after posting 5.3 percent growth in 2018, according to the Central Statistical Office.
Amid the coronavirus disruption, the Polish economy is expected to contract by 4.6 percent in 2020 as a whole, under a budget revision proposed by the government.
Polish Finance Minister Tadeusz Kościński said this month that the projected 4.6 percent contraction would mark the smallest drop in the 27-nation European Union.
"Next year we forecast that we will rebound by about 4 percent, so by the end of next year we will be in the same place,” Kościński was quoted as saying.
Poland’s central bank last month updated its GDP growth forecasts for the country, saying it expected the economy to contract by 5.4 percent this year, followed by 4.9 percent growth in 2021.
The European Commission forecast in July that the Polish economy would shrink 4.6 percent in 2020 amid the coronavirus crisis but then rebound to expand by 4.3 percent in 2021.