“To bring about change, we must change ourselves by being law-abiding citizens,” he said in an address to mark 55 years of independence.
Mr Buhari was a military ruler in 1984 and 1985, and ordered civil servants who were late for work to do frog jumps as he tried to impose discipline.
He returned to office in May after winning democratic elections.
Nigeria is Africa’s most populous state, and the continent’s main oil producer.
However, most of its citizens live in poverty, and the country often faces fuel and electricity shortages.
“Change does not just happen,” Mr Buhari said in his first address to the nation since becoming president.
“We must change our unruly behaviour in schools, hospitals, market places, motor parks, on the roads, in homes and offices,” he added.
He did not give any details of policies he would introduce to encourage the change of behaviour.
In the 1980s, as well as the public humiliation of civil servants, he also deployed soldiers to force Nigerians to form orderly queues while waiting for public transport.
Mr Buhari strongly defended his failure to appoint a cabinet some four months after taking office, saying he did not want to act in a “haphazard” way.