In November of 1875 a former Presbyterian church on Penn Avenue between 15th and 16th streets was purchased. The building was consecrated and became Saint Stanislaus Kostka church. The first ethnic Polish Catholic church in Pittsburgh. The first pastor was a Passionist priest, Father Anthony Klawiter. A school was established in the church basement with lay parishioners serving as teachers. In 1877 Father Klawiter left the parish. For the next nine years the parish was served by a number of priests primarily Passionists and Benedictines. In 1886 the Holy Ghost fathers were assigned to the parish. The Spiritan Fathers served the parish until 1997.
In 1887 the original church building was sold and a school, church and rectory were built at 22nd and Smallman Streets. In 1888 five Sisters of Saint Charles Borromeo came from Silesia in Poland to Pittsburgh to take charge of the school. In 1891, 13 acres were purchased in Millvale for the parish cemetery and the property at the corner of 21st and Smallman was purchased for the new church. Under the Sisters of Saint Charles Borromeo, the school enrollment grew from 300 to 700 students within four years. At the same time, so many young women of the parish became interested in joining the sisters that the community soon established its first American novitiate and began accepting postulants.