The amount showed the ex-military ruler and minister of petroleum had been living a “Spartan lifestyle”, his spokesman Garba Shehu said.
The BBC’s Will Ross says the assets are loose change for Nigerian politicians but a fortune for most of the country.
Mr Buhari is the first opposition candidate to win a national election.
The former military ruler was elected in March largely on a promise to tackle corruption and insecurity.
Corruption is a major problem in Africa’s biggest economy and last month, Mr Buhari said that $150bn (£100bn) was missing from state coffers.
- Five homes and two mud houses, as well as farms
- An orchard and a ranch with 270 head of cattle,
- 25 sheep, five horses and a variety of birds
- Shares in three firms
- Two undeveloped plots of lands
- Bought two cars from his savings