Tamino Tudoras stayed with his grandmother on Monday night in Wilhering, and left her apartment on Tuesday morning to make his way to the Waldorfschule, but never arrived.
His grandmother told police that his behaviour had been as normal and that it is completely out of character for him to disappear.
Tamino is 1.3 metres tall, thin, with short brown hair. He was wearing a yellow hat, an orange winter jacket, blue jeans, and carried a black satchel.
Police have asked anybody who has seen Tamino, or may know where he is, to call the State Criminal Investigation Department, on 059133/403333, or Leonding police station on 059133/4136.