The founder of Rhema Bible Church and Training Center in Broken Arrow became seriously ill over the weekend.
A ministry spokesman says 86-year-old Reverend Kenneth Hagin Senior is in critical condition at a local hospital.
The spokesman says the family is by his side.
Hagin brought his ministry to Oklahoma in 1966. Since then the church has grown to more than 8,000 members and the school has graduated more than 23,000 students.