By the time of the Sixth Assembly of the WCC there will have been over twenty years of official contacts between the World Council and the Roman Catholic Church. The Joint Working Group, established in 1965 to serve this relationship, has already submitted four official reports to its respective authorities. The first three simply recorded what had been done in study and collaboration. The Fourth Report, presented to the Fifth Assembly of the WCC in 1975, also looked ahead to what should and could be done. This Fifth Report is presented in the same spirit.

Further, the last seven years have been crowded with church and world events which have deeply influenced the one ecumenical movement and which call for more widespread and stronger commitment to its goals and its tasks. These events are first outlined here, in order that realism may mark the evaluation of past collab­oration between the RCC and the WCC and the projections for their relationship during the next decade.