The bill would have extended until May 2027 the deadline for doctors from outside the EU to submit proof of Polish language skills at B1 level.
Under the existing rules, those working in Poland on a conditional licence faced a May 2026 deadline, and the amendment would have ensured they did not lose the right to practise if they missed it.
The health ministry argued the extension was needed to prevent staffing shortages in hospitals.
In a video published on social media, Nawrocki said the language issue was a matter of "health security and quality of treatment," warning that misunderstandings between doctors and patients could lead to tragedy.
He criticised the government for attaching the language provisions to an otherwise unrelated piece of legislation – a move he called a "dirty add-on".
"Every Pole has the right to expect that they will be able to communicate effectively and without obstacles with their doctor," Nawrocki said.
The bill also contained measures to improve access to HIV treatment for uninsured patients and to change how hepatitis C screening is funded for prison inmates.
The president said he supported those elements and submitted a separate bill to parliament covering them.
The health ministry had warned the veto would leave uninsured HIV patients and prisoners with hepatitis C without access to healthcare, calling it a significant epidemiological risk.
The Polish Medical Council, the profession's self-governing body, welcomed the decision.
Its president, Łukasz Jankowski, said effective communication between doctor and patient was "one of the basic conditions for safe treatment" and that transitional exemptions from standard requirements could not be extended indefinitely.
(ał)
Source: PAP