Nigeria leader, Muhammad Buhari returned home Friday after almost six weeks of sick leave in the UK.
Buhari, 74, was seen on TV walk unaided from his plane after it landed at an air force base in the northern city of Kaduna.
The former military ruler left Nigeria in January and has been on medical leave in London.
Details of his condition have not been disclosed.
Images released by president’s office showed a thin Buhari smiling.
Buhari left Abuja on Jan. 19 for 10 days of treatment in Britain but extended his stay on the advice of doctors.
In Buhari's absence, Osinbajo, a lawyer, played a prominent role, chairing cabinet meetings and finishing work on an economic reform plan needed to secure a World Bank loan to help plug a deficit caused by low oil revenues.
The central bank also devalued the naira for retail customers, suggesting a wider devaluation of the currency may be in the offing despite Buhari's entrenched opposition to such a move.