The Immaculate Heart of Mary Church in Mahwah, New Jersey was established in the fall of 1915 as a place of worship for Polish immigrants living in Mahwah and the surrounding areas.  The founding Pastor, Father Thomas A. Patalong, S.D.B., was a member of the newly established Don Bosco High School, also founded in 1915 for Polish speaking youths.  The Mahwah Parish became a haven for newly arrived immigrant families from Poland.  The extraordinary care and concern of these families by the many Salesians who staffed the parish accounts for the present day demonstration of devout faith to Our Lord Jesus and the Immaculate Heart of Mary.  The Polish traditions, and adherence to Catholic church doctrines and devotions is still a landmark of the parish community.

The parish has made many transitions since the founding fathers began this great missionary work.  The Salesians of St. John Bosco continued to staff the parish up to the fall of 2002.  From the humble beginnings of a tiny church, a school, convent and rectory were added to the facilities.  The last addition was the replacement of the original wooden church with a truly magnificent church that reflects the devotion and traditions and the tremendous faith of this parish community.  Throughout the years, the influx of young Catholic families to this area has changed the scope of the parish.  The composition of the parish is becoming multi ethnic.  The worship services are now almost exclusively in English.  Of the 1 weekday Mass, and 6 weekend Masses, only one Sunday Mass remains in Polish.

In the fall of 2002, the Salesians withdrew from the parish. It then came under the auspices of the Archdiocese of Newark.  The magnificent spiritual and cultural traditions of  the past are melded now in the present.  The spiritual richness of the community continues to attract a flow of new parishioners.  The motto "To Jesus through Mary" is as vibrant today as it was to those who first heard it in that tiny little Church of the Immaculate Heart of Mary in 1915.