Magar's family initially filed a claim when he was 14, but it was rejected because he was not an adult and there was a chance he might grow.
"We are going to Italy to try to record his name in the Guinness Book of World Records," his father, Rup Bahadur Thapa Magar, told reporters in Katmandu. They plan to appear on an Italian television show to talk about his bid for the title.
Once in Italy, Magar, his father and a supporter will decide on their next destination.
His supporters saw him off from the Nepalese capital on Sunday, offering flower bouquets and garlands.
The current record is held by He Pingping of China, who is 29 inches (73 centimeters) tall.
