Continuity: In one scene at the table Agnes is holding a fork with her left hand. On the next shot, she's holding the fork with her right hand.
Anachronisms: When Oskar and Maria are at the beach, a modern day cargo ship is clearly visible in the background, although this movie is set around 1937.
Anachronisms: In the scene where the German soldiers besiege the Polish post office near the end of the film, a German soldier is seen firing an MG42 machine gun from his shoulder. The weapon itself was not in use by the German army before 1942, while the scene in the film takes place in 1939.
Continuity: When Oskar breaks the teacher's glasses, the pattern of spots on his face change.
Continuity: When Agnes eats eels, a brown bottle is not visible in one cut, even though other nearby objects on the table can be seen. In the same series of cuts, the position of her empty glass and Alfred's beer glass also change.
Anachronisms: WWI Breaks out, and after 2 years of war Oscar's father (biological father - Mother's cousin) reaches the military age and is checked out by military doctors if he is suitable for duty. When he left military hospital there is a soldier in the sentry box who wear WW2 type helmet (M1935 - STAHLHELM) instead of WW1 type helmet (M1916 - Stahlhelm). M1935 released in 1935 and they had more compact shape than M1916