In 1865, a year after St. Xavier's Church was completed; the Society of St. Vincent de Paul under the presidency of an eminent lay catholic, T.C. Loughnan, Esq., took up the matter of education under its serious consideration and set up a special School Committee with Mr. Charles Cook as its chairman. At its meeting of December 27, the Committee passed the following resolution that was forwarded to Bishop Steins. "That as the want of an additional English School for boys, this has been a long felt need by the inhabitants of Poona, an effort to establish such an institution be made without delay." The Committee opened a subscription list for the necessary funds and the Cantonment authorities agreed to give gratis a piece of land on the East Street. However, both the subscription and the piece of land were inadequate and so a year later on December 15, the Committee proposed a new plan to the Bishop. The proposed St. Vincent de Paul's Boys School would be started by the Bishop with the active collaboration of the Society which "resolved to guarantee to Your Lordship a monthly sum of Rs.100 with a proviso that should we be able to make up the balance of Rs.50 as originally promised, the same will be made good. We further bind ourselves to collect and make over to Your Lordship the sum of Rs.3123 already subscribed and to endeavour to continue making up the stipulated sum of Rs.8000." To this the Bishop agreed.
In March 1867, news arrived in Poona that Bishop Steins was being promoted and sent as Archbishop of Calcutta, and so the Poona Conference of the St. Vincent de Paul Society requested that it be allowed to name the upcoming school as "Bishop Steins Boys' School" in order to perpetuate, as they wrote "your name as a friend and Patron of Education which you have proved your self to be ever since your arrival in Bombay". The name of the school, however, was never changed and Mr. Charles Cook agreed to give up his own bungalow (at the site of the present school library) for the purpose of the school. It would be rented for Rs.50 per month.
On Friday, April 5, 1867, Mr. Cook shifted from his house to a new one and next day two Fathers arrived from Bombay to start the school: Joseph Brunner and John McDonnough. The school was started on Tuesday, April 9, with just 5 pupils. The very next day, Fr. Brunner wrote to the Bishop: "Boys are coming every day, though they are not numerous till now. On Sunday last, St. Vincent's School Commission met and showed most zealously to give us any kind of help and encouragement, which in faith we are greatly in need of. The Rs.50 Your Reverend gave me are gone to the last farthing and I can defy all the filoux de Paris and de London to rob me of money..."A month later, Fr. Brunner had more interesting details to give to the Bishop: "Alas, the days are so short here in St. Vincent's School and yet rather than complain we give thanks to God that however short they are - we have nearly fifty boys all well disposed and doing nicely. I received these poor Portuguese (Goan) boys, many of them without parents, or sons of butlers and cooks for One Rupee per month, which all paid most willingly in advance. For the others the fees are at Rs.4 for one chap (T. McDonough's) and Rs.3 for mine. But I am in need of an assistant teacher who be sent without delay.... My money nearly gone again, as I paid to Mme. St. Catherine (Superior of the Convent) a bill of Rs.66.4 for things she purchased for us. From St. Vincent's Society no cash has been received as yet, as they will be able to collect some only in about a months time, people being absent from Poona now. Besides our support, we should have furniture, cots, chairs, table, chest of drawers etc. I suppose you will hardly be able to send us many things. I hope we'll go on well and the school will be a success."
Mr. Cook's bungalow was purchased in August 1867 for Rs.12,000. But the increase in the number of the students and the fact the "purchased spot is much exposed and infected by the poisoned air that arises from the outhouses in the rear of the Police Barracks", compelled Bishop Meurin to apply to the Cantonment for a piece of land in the neighbourhood of Liberty Cinema. The request was turned down and consequently a wing had to be added (ground floor of the old "Red Building"). Its inauguration on January 10, 1868 was reported by the BOMBAY GAZETTE (January 14) in the following glowing terms: "The new school-room of the Society of St. Vincent de Paul was blessed and declared open a few days ago. It is a spacious, elegant and substantial structure, and has sprung up as it were by the touch of a magical wand. Wonderful people, these Jesuits! Nothing appears to checkmate their progress. The word 'impossible' after the great Napoleon is not to be found in their vocabulary. Within a period of a few years, look at their convents, chapels, schools, etc., certainly their energy is exemplary, for they fully demonstrated the saying of the great Prince of Painters - nothing is denied to well directed labour, and nothing can be attained without it." Naturally, the same year the Government recognised the school, and sanctioned Rs.936 as grand-in-aid.
As the number of pupils kept on increasing, more classrooms had to be constructed. In 1882, a top storey was added at the cost of Rs.14,000 and a year later Payne's Bungalow (near the present cycle-stand) was purchased for Rs.4000 and used for Jesuit Residence. In 1909, the roof of this bungalow collapsed, almost killing Fr. F.X. Gallati. The adjoining Meade's bungalow was bought and within a year Br. Joseph Heagele put up a new residence for the Fathers. The second floor was added in 1935-36).
In 1908, the school purchased Hanson's bungalow (parish hall compound) and in 1922 exchanged it for Lavina Hall or Luxa Bungalow, which the Bishop had earlier purchased from a certain Laxman. This bungalow was turned into a boys' hostel and finally replaced by the Gulati Hall. In 1920 a porch was added to the Red Building and a wing towards the West. The work progressed fast and the Governor of Bombay, Sir George Lloyd, inaugurated the new wing on the feast of St. Vincent, July 19, 1921. Two years later, the play-field beyond Maneck Nullah (dividing the city from the Cantonment) was acquired for Rs.22,000 and the nullah covered in the early sixties. Fr. Riklin constructed the imposing wing with the statue of the Patron Saint from 1933 to 1935, and 25 years later Father Schoch replaced the original Red Building with the present office block, library, laboratories and classrooms, completed in 1963 at the cost of Rs. 8,41,910. Soon after, the AV Room was furnished and the stadium built in time for the Centenary Celebration in 1967. In the year 1977, Fr. Edmund D'Souza extended the primary section by one floor. Fr. K. Misquitta constructed the second storey of the building in 1985. Extension of the stadium started in October 1999 and was completed in May 2000 by Fr. K. Misquitta.