Cappella del Miracolo del Sacramento, Chapel in the church of Sant'Ambrogio, Florence, Italy

Cappella del Miracolo del Sacramento is a chapel within Sant'Ambrogio Church featuring a marble tabernacle created by Mino da Fiesole and frescoes painted by Cosimo Rosselli in the 1480s. The space sits elevated on steps beside the main altar, enclosed by marble railings that define its boundaries.

The miracle occurred on 30 December 1230, when the elderly priest Uguccione found living blood in the chalice he had failed to dry after Mass. Bishop Ardingo kept the crystal ampoule in the episcopal palace for a year of checks before returning it. In 1345 the wool merchant Turino Baldesi gave 3,000 gold florins for a chapel to hold the relic; the present one was arranged in 1481, with Mino da Fiesole's marble tabernacle and Cosimo Rosselli's frescoes painted between May 1484 and August 1486.

The chapel's name comes from the Eucharistic miracle of 30 December 1230, when the priest Uguccione found living blood in his chalice; the ampoule became an object of popular devotion. The feast was long promoted by the Arte dei Giudici e dei Notai, which funded the anniversary celebrations from 1317 to 1344. In 1340 the blood was carried in procession to ward off a plague.

The chapel is easy to locate within Sant'Ambrogio Church and offers a quiet experience beside the main worship space. Visitors should remember this is a sacred area and respectful conduct is expected.

The crystal ampoule stayed on the high altar for over a century before Domenico Maringhi, a descendant of the prior Francesco Maringhi, had a new tabernacle built to the right of the entrance in 1468. The Baldovinetti panel that framed it, with Angels and Saints Ambrose, Lawrence, John and Catherine of Alexandria, later moved to a nave altar.