The diocese of Idukki belongs to the Syro Malabar rite. It has an area of 3,000 square kilometers comprising Idukki district in Kerala surrounded by the eparchies of Kothamangalam, Kanjirappally, Palai and the archdiocese of Madurai. The Catholics of the diocese belong to the ancient St. Thomas Christian community.
The total population of the diocesan territory is 1,129, 221. Idukki has been a multi-ethnic and multi-religious region.
Malayalam and Tamil are in use in the diocesan territory.
The history of the Church in Idukki district begins with the migration of the people from other parts of Kerala to this high ranges in search of fertile land to cultivate. When the diocese of Kothamangalam was established in 1956 there were only 17 parishes in the high ranges. In 1963, the high range mission region was divided into four foranes. Pope John Paul II erected Idukki diocese in 2003 by bifurcating the diocese of Kothamangalam on Jan. 15, 2003, and Father Mathew Anikuzhikattil was appointed as the first bishop of the diocese.
The territory is connected via roads only. There are some places in the district which are not accessible even by roads. The nearest airport is in Kochi which is 110 kilometers away from the district and the nearest railway station is at Kottayam which is 114 kilometers away.
The diocesan territory has moderate climate, with temperature varying between 0 to 30 degrees Celsius. The district receives plenty of rain from both the South-West monsoon during June-August and the North-East monsoon during October-November. The normal rainfall is 3265 mm.
The economy of Idukki diocese is mainly based on agriculture. Animal husbandry is the secondary source of income. Idukki is an industrially backward district in Kerala.
Though most of the homes have television and telephone connections, access to the internet is limited. There are no television and radio broadcasting stations in the diocesan territory.
The name of the district Idukki is derived from the Malayalam word idukku which means a narrow gorge. The diocese is covered by the mountains, hills and dense forests. Because of its special landscape it is also known as the diocese of the mountains. High ranges vary in altitude from about 600 meters above sea level to more than 1,800 meters.
Literacy rate in the diocesan territory is 88.69 percent, higher than the national average of 59.5 percent.