It was possible up to 1.11.2004, but not any more.
What are the time limits to enter the national phase under the Chapter I and Chapter II of the PCT?
What is required to enter the national phase of an international patent application under the PCT in Poland?
EP validation in Poland
When a Polish patent attorney is sufficient and when do you need a European patent attorney?
Patent Claim Interpretation - Global Edition (Polish Chapter)
Fee changes for trademark prosecution in Poland