The territory of this Province is almost co-extensive with the territory of the Archdiocese of Changanacherry and that of the Diocese of Thuckalai except some portions of the foranes of Athirampuzha,Nedumkunnam and Manimala.It comprises of the revenue district of Kanyakumari in Tamilnadu and the revenue districts of Thiruvananthapuram,Quilon and major portions of the revenue districts of Pathanamthitta,Alleppey & Kottayam in Kerala.
At present the area covering the revenue district of Kanyakumari,co-extensive with the Diocese of Thuckalai, is a dependent Sub-Region of the Province. The boundaries of the two Provinces bearing the name of St. Joseph coincide in the municipal town of Kottayam.
