The group, restricted to Roman Catholic priests, was founded in 1990 by six priests. They included Father Gabriele Amorth, known as the "Exorcist of Rome," who claims to have performed 160,000 exorcisms -- the ceremonial process of releasing demons from those possessed by them.
The organization now has 250 members in 30 countries.
Roman Catholic exorcism procedure requires a priest's consent from his bishop, and examinations by medical specialists to determine if a victim's medical or psychological issues can be treated by non-religious means. The Church issued a revised guide to exorcism in 1999.
The practice was brought to the attention of the non-Catholic world in 1973 by the film The Exorcist.
"The approval by the Holy See is a joy not only for our association but for the church as a whole. We hope more priests will realize the existence of this dramatic reality, which is often ignored or underestimated. Exorcism benefits people who are suffering, and is doubtless a work of bodily and spiritual mercy," exorcist Father Francesco Bamonte told L'Osservatore Romano, the official Vatican newspaper, Wednesday.