The children died at three hospitals in Lagos, Ibadan and Zaria.
At least 10 other children are reported to have been brought to hospital.
Nigeria's food and drug agency says that 25 children aged between three months and four years
have died after taking a contaminated teething syrup.
The substance, used in engine coolant and anti-freeze, triggered kidney failure in the children.
symptoms among the children who had taken the syrup included diarrhoea, vomiting, fever
and convulsions, and that they had not been able to pass urine for several days.