Demonstrators held up traffic on key routes including Trasa Łazienkowska and at de Gaulle roundabout, from where hundreds marched to the parliamentary buildings in the capital, state news agency PAP reported.
They carried banners with slogans such as "Freedom of choice" and "Revolution has a womb".
Street protests have been held across Poland since October 22, when the country’s Constitutional Tribunal ruled that abortion of a malformed foetus violates the constitution.
The biggest demonstrations took place on Friday evening, even though President Andrzej Duda earlier that day said he had submitted a bill that would mean less severe rules than the near-total ban on abortion signalled by the tribunal’s ruling.
Prime Minister Mateusz Morawiecki has issued a plea for protests to be called off amid a surge in coronavirus cases.
Poland reported 15,578 new infections on Monday and 92 more deaths. The figures indicated a slowdown in the daily rate of new cases.
On Saturday, Poland reported a record rise in coronavirus infections for the fifth consecutive day, confirming 21,897 new cases, the most since the pandemic hit the country in early March.