Caritas Archeparchial Secular Institute for women, the first Seculer Institute in Kerala, was formally started by the  Bishop Mar Thomas Tharayil on 13th May 1961(vide: Decree No. B 69/62 dated 13th May 1962; Decree No. B 286/63 dated 3rd September 1963). Its Constitution and Rules were approved by the Holy See as per Prot. No. 409/61 dated 28th February 1963(Const. No.4).

The idea of founding a Secular Institute in his Diocese was blossmed in the mind of Bishop Thomas Tharayil more than a decade ago of 1961 and he was searching and studying the development of Secular Institutes, a new phenomena in the history of the Church.

Since Secular Institute was alien to the Indian culture, he was keen on having this new plant take its root in the Indian soil, filling to the Indian culture. Mar Thomas Tharayils great love & concern for the sick and the poor prompted him to think of the new institute as one primarily dedicated to the apostolate of health care and social work. At the same time there was no well equipped hospital in central Kerala except a Govt. hospital where the staff could not do justice to all the patients due to so many reasons. These inspired him to start a well-equipped hospital. With this two ideas in mind he met people, discussed the matter and made a thorough study. He even prepared people beforehand in view of starting a Secular Institute and a hospital . Some girls came forward and they were given some basic knowledge of life as a Secular Institute member and were sent for medical studies  abroad.  Dr. Mary Kalapurackal is one among them now working in Caritas Hospital.

As a result of his study & discussion with Cardinal Tissarent, Secretary of the Sacred Congregation for the Oriental Churches Rome, permission was granted to start the Caritas Secular Institute.

Mar Thomas Tharayils contact with and visit of certain Secular Institutes in Europe helped him to concretely articulate and work out his desire to found Secular Institute in his Diocese(Const. 6).