Burundi's bishops said that "after considering the manner in which the elections have been organised and the way they are evolving" it would not be appropriate to hold a vote now.
The African nation is in crisis after violent protests and an attempted coup to oust President Pierre Nkurunziza.
The president is attempting to stand for a third term in office, a move which opponents say violates the terms of the country's constitution.
Yesterday opposition parties said it was now "impossible" for a free and fair election to be help prompting the Church to urge its priests to resign from the electoral commission.
The Church said it "cannot endorse an election riddled with shortcomings" but added that people should vote if they don't feel threatened or intimidated to do so.
"In the eyes of God, that would be slavery to evil," it added.
At least 30 people have died in violence over the past month.
The Catholic Church has huge influence in Burundi with 62% of people identifying with the faith.