Local media reports Tuesday said Netanyahu's 18-year-old son boarded a bus at a Jerusalem induction center, beginning a compulsory three-year stint.
Yair will be the only soldier in the army with the rank of private who will be accompanied by a bodyguard, the reports said.
Some reports said a dispute arose between Israel's security service and the army over who will be responsible for Yair's safety.
In the end a compromise was reached whereby it was decided the army will be in charge when he is on base and the secret service will accompany him when he is on leave, Yedioth Aharonoth said.
Yair will join the army's spokesman's unit, the paper said, but will first have to go through three weeks of basic training and then attend a second course where he will learn the skills needed for his post.
In Israel, military service is compulsory for all citizens except those who are exempted for religious or health reasons and can do national service or community work instead. Israeli males are required to do three years of military service and females two years.