The two countries have been at odds in Brussels since last week over population-based EU voting rights.
Poland claims Germany killed 6 millions Poles in World War I, and alleges Germany is trying to dominate the union, the EU Observer reported.
"Something bad is happening in Germany. As in historic days gone by when most Europeans were too afraid to talk, so it is today," Kaczynski said on a national radio program.
He was responding to a sarcastic remark about Poland's claim of war dead in a German newspaper about "the square root of the dead," the report said.
German politicians have said little about the dispute but newsman Tom Buhrow said on national TV that Poland is "feeding on its western neighbor," referring to $80 billion in EU funds allotted to Warsaw by 2013.