Sisters are active, vowed religious women who are members of over 25 different congregations in the US. At the basis of all their activity is the primary apostolate of preaching that takes many forms: teaching, social work, missionary work, advocacy for the poor, care of the earth, housing ministries, retreat and spiritual direction, the arts, just to name a few. In common with the other branches of the Family, Sisters pray the Liturgy of the Hours, observe a regular practice of prayer and study, and share community.

Many Dominicans sisters' congregations enjoy an enriching relationship with Associate members who participate in the congregation's charism, Dominican spirituality and tradition. In this way, Dominican charism is extended even wider.