In 1982, the Diocese of California made an arrangement with Saint Mary's College of California, approved by the papal nuncio, which allowed for St. Giles to worship in the chapel at St. Mary's College.

Saint Giles continues to worship in the chapel at Saint Mary’s College and engages in regular ecumenical dialogue with the students, faculty, staff, and Lasallian brothers who live and work at the college.

Saint Giles’ primary worship service is a celebration of the Holy Eucharist, held Sunday mornings at 9:00am.

Other rites and sacraments celebrated throughout the year include baptism, confirmation, matrimony, funerals and memorial services.

Each year, on the Sunday closest to Saint Giles' feast day, the congregation held an outdoor Eucharist at Moraga Commons and on the Sunday closest to St. Francis of Assisi’s feast day, the congregation held a blessing of animals which drew people from throughout the local community.