Anachronisms: The bayonet used by the German sergeant to open the sack of beans is not German issue. It appears to be a Turkish Model 1890 bayonet.
Anachronisms: Early during the movie, when the family is listening to a BBC radio broadcast in the autumn of 1939, there's a brief overlap during which we hear a few German words being spoken. These are from a recording of the infamous Sports Palace speech by Joseph Goebbels, delivered in Berlin on 18th February 1943 - well over three years after the movie's scene takes place.
Continuity: When Szpilman is told he has to leave the first apartment he's hiding in, his hair is parted and hanging down either side of his face. In the next shot, when he sits down to try to smoke the cigarette, his hair is combed back with no part visible.
Continuity: When Szpilman is forced to leave his first hiding place after breaking the dishes, he has significant stubble on his face. However, when he reached Dorota's apartment in the next scene, he's clean shaven.
Continuity: When Szpilman crawls past the woman who was shot in the back and died kneeling in front of the hospital (before she reached the staircase), she has moved forward visibly (and is now in front of the stairs).
Anachronisms: When Szpilman is playing in the closing scenes, the piano's logo "Steinway & Sons" is the modernized style that came into use in the 1990s.
Continuity: When Szpilman is crossing the bridge, the same extra (wearing the glasses) passes him twice, in the space of two shots.
Anachronisms: When "the pianist" goes to his friend of last resort for help it is deep winter in Poland with snow. On the table in his friends flat is a bunch of fresh yellow roses. How do you get roses in mid-winter wartime Poland? Also, the following morning the roses have mysteriously changed to apricot-colored roses.