The Turk who shot and wounded Pope John Paul II in 1981 has laid flowers on the saint's tomb in St Peter's Basilica, the Vatican said.
A Vatican spokesman, Father Ciro Benedettini, said the surprise visit on Saturday by Mehmet Ali Agca lasted a few minutes.
As with other flowers left by visitors to the tomb, the white blossoms were later removed by basilica workers.
John Paul visited the incarcerated Agca in 1983 and later intervened with Italian authorities to gain Agca's release in 2000 from the Italian prison where he was serving a life sentence for the assassination attempt in St Peter's Square.
Agca then served a sentence in Turkey in another case and is now free.
Fr Benedettini said there are no legal matters pending against Agca in the Vatican.