The Orton-Gillingham reading-intervention program (OG) is widely used for children with Reading Difficulties (RD). However, few studies have been performed to evaluate the effectiveness of the OG. Here, we examined the effects of the OG on oral and silent reading in children with RD. Children with RD who participated in the OG showed similar improvements in speed and accuracy of oral reading after training as did children with RD who participated in the control program. Both groups showed improvement in oral reading speed. Children in the OG group did show greater accuracy in oral reading compared to silent reading. These results suggest that the gain from the OG was not different from participation in another intervention program in improving oral and silent reading speed.