As it is known, the duty of the Presidency of Religious Affairs is expressed in the related law as to enlighten society on religion, to carry out the activities related to the fi eld of belief and worship of Islam and to manage places of worship. In order to carry out these services more effectively, the Presidency re-educates the personnel it employs in their training centers. The related personnel are included in the in-service training programs which are different in terms of time and content. One of these in-service training programs is the “Tashih-i Huruf” educational program. In this study, the objectives, content and effectiveness of the “Tashih-i Huruf” inservice training program has been investigated. In this respect, the content of the program has been analyzed and it has been tried to be measured by the fi eld research which effected the program on the participants. The research was conducted on 93 trainees who attended Samsun Asikkutlu, Sanlıurfa İbrahim Khalilullah and Bolu Educatioan Centers in the academic year of 2017-2018.