The delegates accredited to vote at the primary poll totaled 3, 221.
"Congratulations to Former Vice President of Nigeria, His Excellency, Alhaji Atiku Abubakar on his emergence as the flag bearer of our great party, the People's Democratic Party".
Abubakar garnered 1,532 votes, trouncing his closest rival Aminu Tambuwal, the governor of northern Sokoto state who scored 693 votes.
"All the doubting Thomases that thought we would all walk out after the results have been announced, we are not going anywhere but walking with Atiku to victory".
A few hours after President Muhammadu Buhari received the ticket of the All Progressive Congress (APC) seeking re-election in 2019, the First Lady, Aisha Buhari took to social media to express her displeasure over the "impunity" taking place in the ruling party. "The task to get Nigeria working again starts now", Abubakar said in a tweet.
Political parties had until Sunday to select their candidates. It emerged from recession early a year ago but growth remains sluggish and inflation above the central bank's single-digit target range.
He described President Muhammadu Buhari as clueless, adding that the PDP can not afford to fail at the general election.
The ex-vice president, who is from the northeastern state of Adamawa, in May told Reuters he would privatise parts of the state oil company and allow the naira currency to float to attract foreign investment if elected as head of state.
But next year's presidential race appears to have tightened in recent months with the APC hit by a wave of defections over Buhari's leadership style.
"Our just concluded convention was a partisan event which the country can show-case as an example that democracy has a future in Nigeria and that when we are determined we can elect our leaders without any manipulation, intimidation and violation of the law and democratic norms".