At the time of the establishment of the diocese, there existed five parishes in Canada: St. Gregory the Illuminator (Montreal), Holy Trinity (Toronto), St. Gregory the Illuminator (St. Catharine´s), St. Vartan (Vancouver), St. Mary (Hamilton).
The marked shortage of clergy was rapidly remedied, and new parishes started to take shape in the subsequent years. By early 1990s new parishes were established: Holy Cross Armenian Church in Laval, a suburb of Montreal, was the result of rapidly growing Armenian community in that area. The parish was established by Arp. Hovnan Derderian in 1993. A plot of land with a house on it was purchased in 1998, which still serves as a temporary church for this parish.
St. Vartan Armenian Church of Mississauga, Ontario, was established in 1990 by Bishop Hovnan Derderian, Primate, as a reason to increasing number of Armenians in this area close to Toronto. Church services are conducted in a rented church, but plans are being pursued to acquire a plot of land for the construction of a church.
Newer and smaller communities have come to life in distant locales of this vast country, and the Diocese has strived to support them to be organized into Mission Parishes. These communities don’t have a potential to grow and cannot support a full time pastor. A three-member representation, appointed by the Primate and the Diocesan Council, maintains communication with the Diocese. On special occasions or major feasts, visits by the Primate or the Vicar General to these mission parishes are greatly appreciated by the local Armenians. At present there are seven Mission Parishes: Halifax (Nova Scotia), Winnipeg (Manitoba), Edmonton (Alberta), Calgary (Alberta), Kingston (Ontario), Quebec (Quebec), Yellowknife ( Northwest Territories), St. Mesrob (Ottawa) and Holy Ressurectioan (Windsor).