The diocese was constituted on 10 March 1985, by Kalpana No. 52/85 of Catholicos Baselios Marthoma Mathews I. Its parishes are concentrated around Chengannur, Pandalam, and the surrounding Pamba river region.
Counts above reflect Orthodox-held institutions only; churches, chapels, and other properties currently under schismatic occupation are catalogued separately below and are not included in these totals.
5 districts, listed alphabetically.