Pope Francis says that it may be acceptable, or even "morally necessary", for married couples to split up if they are at war with each other.
The head of the Roman Catholic Church, an organisation that has traditionally been implacably opposed to divorce, said there was even greater justification for separation in cases where the wife was being abused by her husband.
The Pope made the remarks ahead of a crucial bishops' conference, or synod, in the autumn in which contentious issues such as whether to give communion to remarried divorcees will be discussed by the Catholic hierarchy.
"There are cases in which separation is inevitable," the Argentinian pontiff said during his weekly general audience in St Peter's Square.