The church, now classified as a basilica, is located next to the hospital (1552) and was built between 1737 and 1759. The floor plan of the building is in the shape of a Latin cross – a single nave with two side chapels either side, a transept, a main chapel and choir.
The interior is richly decorated with gold, silver, beautiful altarpieces, mural paintings, cornucopias and lights. The transept and chapel altarpieces, the frescoes by Diego Sánchez Sarabia and the main chapel altarpiece, where the mortal remains of Saint John of God lie, are outstanding.