In a land area of 145,663 square kilometers, the diocesan territory covers the civil districts of Greater Bombay, Thane, Raigad, Pune, Kolhapur, Satara, Solapppur, Sangli, Sindhudurg, Ratnagiri, Nasik, Dhule, Jalgon, Nandurbar and Ahmednagar in Maharastra.
Bombay is the biggest city in the diocese. Pune, Thane, Kolhapur, Nashik are the other are other important cities and towns in the diocese.
48,570,844 is the total population in the diocesan territory. Marathas form the major ethnic group. Marathi, Hindi, Malayalam, Tamil and English are the languages used in the area.
Marathi, Hindi, Malayalam, Tamil and English are the languages used in the territory of Kalyan diocese.
Since it encompases a vast state overlapping many dioceses and Bombay being metro the area has people of all languages.
The history of the Diocese of Kalyan is very much intertwined with the history of the Syro - Malabar Church itself in India. Having its roots in the Apostolic Ministry of St. Thomas the Apostle himself who established seven communities of the Christian Church in Kerala in the first century itself. These Christians migrated to different parts of India. They concentrated mainly in the big cities of India. In Bombay, Pune and Nasik regions, they are found in large numbers. The spiritual care of these regions are assisted by lay association like Kerala Catholic Association (Bombay). St. Thomas Christians of India (Pune).
On Sept. 8, 1978 Pope John Paul II appointed His Eminence Antony Cardinal Padiyara, the then Archbishop of Changanacherry, as the Apostolic Visitor to study the situation. The visit of Pope John Paul II to India in 1986 gave him a first hand experience of the living faith of the Syro - Malabar Christians of India. A Pontifical Commission was appointed and on the basis of its report came the all-important letter of the Pope to the Bishops of India observing that the present situation in Bombay - Pune region is mature for the Churches to take necessary steps in this regard. Finally on May 19, 1988 His Holiness Pope John Paul II made the announcement of the establishment of a new diocese for the Syro - Malabar Christians of Bombay - Pune - Nasik regions, the Diocese of Kalyan, and the designation of Mgr. Paul Chittilapilly as its first Bishop. The Bull, however, was signed by the Pope as on April 30, 1988. Thus the birth of the diocese and the appointment of the first Bishop took effect from April 30, 1988.
The Episcopal Ordination and the official inauguration of the diocese took place on Aug. 24, 1988 at the Don Bosco Grounds, Matunga, Bombay.
After nine years of dedicated and pioneering work in the newly born diocese, Bishop Paul Chittilappilly was transferred to the diocese of Thamarassery in Kerala on Dec. 18, 1996 and took charge on Feb. 13, 1997. His successor and the second bishop of Kalyan Diocese was Mar Thomas Elavanal, whose consecration was on Feb. 8, 1997 at Kannamwar Nagar, Vikhroli, Mumbai.
The Cities are managed by Corporations. The villages and small towns are administered by elected local bodies called Panchayats and municipalities respectively.
The diocesan area is well connected in terms of transport infrastructure by roads and railways. The nearest airport is in Mumbai city (formerly Bombay).
Rupees 15,900 (USD350 as of February 2011) is the per capita income in the diocesan territory. Agriculture, Fishing are the major occupations in the diocesan area.
Government and private operators provide extensive telecommunication facilities in the diocesan area. The diocese is well connected by local cable TV networks.
70 per cent is the literacy rate in the diocesan territory.