He finished high school with a partial matriculation. Vanunu's parents wanted him to attend a higher yeshiva; he agreed but left after a week. He then found a temporary job in the court archives. In October 1971, he was conscripted into the Israel Defense Forces. He tried to join the Israeli Air Force as a pilot, but after having been rejected by examiners, they sent him to the Combat Engineering Corps, where he became a sapper. After basic training, he completed a junior commanders' course, then a non-commissioned officers course, and was given the rank of Sergeant-Major.