Tens of thousands of people marched in Warsaw's Pride parade on Saturday to demand equality for LGBT people ahead of Polish elections.
The country's right-wing government, which is seeking re-election, has focused on opposing what it calls "LGBT ideology" in previous campaigns.
But Warsaw's mayor vowed that the LGBTQ community would "always be safe".
"And I hope that you all will be safe in Poland," Rafal Trzaskowski, from the liberal opposition party, told crowds.
"We want to show that today diversity, minority rights means Europe that is open, Europe that is tolerant," he said at a press conference before the march.
Same-sex relationships are not legally recognised in Poland, and the country already bans same-sex couples from adopting children.
There are also obstacles facing transgender people who seek to formalise their transition.
Poland's ruling conservative nationalist Law and Justice party (PiS) says that extending marriage and adoption to gay couples threatens traditional family structures and is harmful for children.
Activists expect that these issues will be used by the party to mobilise conservative voters in the predominantly Catholic country during this year's elections in October or November.
"I am almost a hundred percent sure that it will be happening again this year," Alicja Herda, one of the organisers of Warsaw's Equality March, told Reuters news agency.
"But I am not very worried because we are a very strong community, and we will not be easy to stop from doing our prides (marches) because it's okay to be who we are."
Joining the large crowds on the march was US Ambassador to Poland Mark Brzezinski and the Mayor of Paris, Anne Hidalgo.
"We will not let ourselves be influenced by those who want to extinguish women's rights, minority rights, LGBT rights, and today, I want to say to you that in Paris just as in Warsaw, we are also totally in solidarity and engaged with you for the rights of transgender people," Ms Hidalgo said.