Morawiecki last month announced a multi-stage loosening of coronavirus restrictions, promising to reopen cinemas and theatres at half capacity on May 29.
That date will be brought forward to May 21, the prime minister said on Wednesday, adding that such facilities will have to operate with anti-COVID precautions in place.
Polish shopping malls, DIY stores, museums and art galleries were allowed to reopen last week.
Officials on Wednesday reported 4,255 new coronavirus infections and 343 more deaths, bringing the country's total number of cases during the pandemic to 2,842,339 and fatalities to 70,679.
On April 1, the Polish health ministry confirmed 35,251 new single-day cases, the most since the pandemic hit the country more than a year ago.