The diocese was formed by the Kalpana (decree) of Catholicos Baselios Marthoma Didymus I, and has been counted among the faster-growing dioceses of the church since. Its parishes cover the Adoor and Kadampanad regions of central Kerala.
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.