"Vote for who you want, change the government, but don't change country," said the prime minister, himself a former scout, at the meeting in San Rossere, near Pisa.
"Stay in Italy, kick out the impossible," he said, adapting a famous phrase from scouting founder Robert Baden Powell, who urged his young charges to "kick out the 'im' from 'impossible'".
With unemployment at 12 percent in Italy - and 40 percent among young people - the government is growing increasingly worried about a brain-drain as the brightest young Italians head abroad for work.
"You must stay in Italy to make the country more beautiful," he told the scouts.
The young premier, 39, who became head of state in February, also defended the ruthless steps he took to oust his predecessor, Enrico Letta.
"Politicians should be like yoghurt -- they have an expiration date. That goes equally for me. The countdown to my being scrapped has already begun," he said.