As in the rest of Europe. And why was it all those years, that there were more Jews in Poland than in any other country?
That's some amusing historical revisionism. Between 1890 and 1920, 2 million Jews left Poland, fleeing Polish pogroms. That's hardly a ringing endorsement.
In the interwar period of anti-Bolshevik Polish independence, there were at least 9 major pogroms in 1918-1919. In 1937, the anti-Communist government of Poland introduced legislation virtually identical to Hitler's Nuremberg laws, banning Jews from many kinds of employment. Between 1935 and 1937, hundreds of incidents of anti-Semitic violence took place, resulting in the lynchings of 79 Jews by Poles. In 1937, Jews were banned from becoming doctors or lawyers.
During the Nazi occupation, Polish civilians rounded up and killed Jews on their own initiative. In 1941, for example, Polish civilians murdered between 350-1000 Jews in and around the town of Jedwabne.
Was antisemitism unique to Poland? Absolutely not.
But in modern times, there has not been a single Pogrom anywhere in Central or Western Europe (excepting areas under control of the Nazis) with the sole exception of Poland.