The Diocese was formed by order number 145/2009 signed by the then Catholicos of the Apostolic Throne of St. Thomas and Malankara Metropolitan, His Holiness Baselios Mar Thoma Didymos I on April 1, 2009. The head quarteres of the Diocese is in Houston, Texas.

The Diocese is constituted of the parishes located in the southern and western states of the United States of America and the western provinces of Canada. The head of the Diocese is the Diocesan Metropolitan also known as the Diocesan Bishop, canonically elected, installed, and recognized by order of the Catholicos.

The Diocese is governed according to Holy Tradition, practices, and the Constitution of the Malankara Orthodox Syrian Church adopted in 1934 and subsequent amendments, (hereafter the Constitution). The Diocese is not an independent church in matters of ecclesiastical discipline or faith, but a part of the Malankara Orthodox Syrian Church and always will remain as such, unless otherwise decided by the Malankara Orthodox Syrian Church.

The purpose of the Diocese is to function as the Central Administrative Body of the individual parishes within its functional jurisdiction and to provide leadership to bring administrative and functional consistency, spiritual harmony, ecclesiastical spread and discipline among the faithful members of the Malankara Orthodox Syrian Church of the Diocese.

The Diocese may engage in various religious, educational, charitable, social, and mission activities allowed to any religious charitable organizations in the United States of America and Canada under applicable law.

The Diocese of South-West America was officially inaugurated on June 13, 2009.  Inauguration events were conducted during the Southern Regional family conference held at the University of Houston.

Holy Qurbana was celebrated by His Grace Alexios Mar Eusebius, Diocesan Metropolitan of the Diocese of South-West America along with His Grace Mathews Mar Barnabas, His Grace Dr. Mathews Mar Severios and over twenty priests, deacons and seminarians of the newly formed Diocese.  His Grace Mathews Mar Barnabas, the Diocesan Metropolitan of the North East American Diocese presided over the inauguration ceremonies.

Along with Their Graces, His Eminence Cardinal Dinero of the Roman Catholic Church, Mrs. Anita Perry, the First Lady of the State of Texas, Mayor Bill White, honorable mayor of the City of Houston,Sanjeev Arora, Consul General of India in Houston, and various other guests from the Orthodox Churches and political dignitaries were present to witness this historic event.