Pope Francis skipped a planned visit to a Rome seminary this evening because he was "slightly indisposed," a Vatican spokesman said.
It was the first time since his election nearly a year ago that the pope has cancelled a public engagement.
Pope Francis will not go to the Roman Seminary tonight because of a slight indisposition with a slight fever," chief spokesman Father Federico Lombardi said in a statement.
"His doctor has advised him to skip the planned event and rest."
Francis, who had part of his right lung removed when he was 21, has shown no signs of ill health since his election on March 13 last year.
The pope was to have addressed priests and men studying for the priesthood at the seminary.