A four year-old Jewish boy was attacked walking home from pre-school, in what's being labelled a race-hate crime.

The boy was approached by a man who slapped him hard on the top of his head in front of his mother, brother and a friend in the Auckland suburb of Mt Eden last week.

Jewish Council president Stephen Goodman says the man was in his 20s with a Middle Eastern appearance.

The child's mother says the man laughed as he left the scene in a car with four others.

Mr Goodman says the attack seems to have been racially motivated as both the boy and his friend were wearing Jewish skullcaps.