The large refectory of Ognissanti is situated between the first and the second cloister of the antique convent. In the room, facing there is a magnificent door, in pietra serena, and on either side two basins of 1480. In the niches there are two frescoes referring to the water: Sara at Jacob's pit and Moses who makes water gush from the rock; works by Giuseppe Romei of the seventeeth century.
The central fresco, which entirely covers the wall measures 8.10 x 4; it is the work of Domenico del Ghirlandaio (1449-1494). He reached one of the best results of his art in the fresco of Ognissanti.
The representation of the Last Supper is calm, but not without drama. The apostles are painted in the moment Jesus announces that one of them will betray him. According to a report by the purchasers (at that time, the refectory belonged to Humiliati Monks), Ghirlandaio has picked out many apparently decorative details, but which, in reality, express a precise symbolic reference to the drama of the Passion and the Redemption of Christ: from the evergreen plants to the flight of the quails, from the oranges to the cherries, from the dove to the pea-cock. As it is a separate fresco it is possible to compare it with the sinopite on the left wall, between the pulpit which was used for the Bible reading during dinner and supper.