Witnesses told Reuters police had tried to control crowds around the Felix Houphouet Boigny Stadium after the celebrations, triggering a panic in which scores were trampled.
"The estimate we can give right now is 49 people hospitalized ... and 61 people dead," said the chief of staff of Abidjan's fire department, Issa Sacko.
Crying women searched for missing family members outside the stadium on Tuesday morning. The area was covered in patches of dried blood and abandoned shoes.
"My two children came here yesterday. I told them not to come but they didn't listen. They came when I was sleeping. What will I do?" Assetou Toure, a cleaner, told Reuters.
Sanata Zoure, a market vendor injured in the incident, said New Year's revelers going home after watching the fireworks had been stopped by police near the stadium.
"We were walking with our children and we came upon barricades, and people started falling into each other. We were trampled with our children," she said.
Another witness said police arrived to control the crowd after a mob began chasing a pickpocket.
“The precise circumstances of this tragic occurrence are being looked into by the security services,” Interior Minister Hamed Bakayoko said on RTI state television, according to the New York Times.
President Alassane Ouattara and his wife visited local hospitals to speak to the injured, the Telegraph reported, and he pledged that the government would pay for their treatment.
“This is a real tragedy on this New Year’s Day,” he said earlier at the scene. “We are all in shock.” He added that a period of national mourning would be held.