To assess the prevalence and causes of childhood blindness in Cross River State, Nigeria, using the key informant (KI) method.KIs were selected and trained and requested to bring children to identified facilities 2 weeks after training for examination by a specialist team. Visual acuity and cause of impaired acuity were assessed. Children at a Cross River State school for the blind were also assessed. An estimated prevalence of childhood blindness and severe visual impairment (BL/SVI) in the Cross River State was calculated.A total of 742 KIs were included. The prevalence of BL/SVI in Cross River State was estimated to be 0.09-0.22 per 1,000 children. The three most common anatomic causes are lens related (35%), whole globe (19.4%), and corneal (15.7%), most of which are avoidable.The prevalence of childhood BL/SVI in Cross River State was somewhat lower than expected but similar to other recent reports from Africa. Lens-related causes were the most common. KIs performed well, ensuring that many children in need of eye services were examined.