Giordano acquired a style fusing Venetian and Roman styles. He combines the ornamental pomp of Paul Veronese with the lively complex schemes, the "grand manner" of Pietro da Cortona. He was noted also for lively and showy colour, and between 1682-83 he painted various fresco series in Florence, including in the dome of Corsini Chapel of the Chiesa del Carmine. In the large block occupied by the former Medici palace, he painted the ceiling of the Biblioteca Riccardiana (Wisdom released from the Slavery of Ignorance) and the long gallery of the Palazzo Medici-Riccardi. The vast frescoes of the latter are contained in the 1670s gallery addition, overlooking the gardens. The planning was overseen by Alessandro Segni and commissioned by Francesco Riccardi. They include the prototypic hagiographic celebration of the Medici family in the center, surrounded by a series of interlocking narratives: allegorical figures (the Cardinal Virtues, the Elements of Nature) and mythological episodes (Neptune and Amphitrita, the Rape of Proserpine, the Triumphal procession of Bacchus, the Death of Adonis, Ceres and Triptolemus)
In Spain he executed numerous works, continuing in the Escorial the series commenced by Cambiasi, and painting frescoes of the Triumphs of the Church, the Genealogy and Life of the Madonna, the stories of Moses, Gideon, David and the Celebrated Women of Scripture, all works of large dimensions. His Dream of Solomon (1693, now at Prado) dates from this period. His pupils, Aniello Rossi and Matteo Pacelli, assisted him in Spain. In Madrid he worked more in oil-colour, a Nativity there being one of his best productions.
Giordano had an astonishing facility, which often lead to an impression of superficiality of his works. He left many works in Rome, and far more in Naples. Of the latter, his Christ expelling the Traders from the Temple in the church of the Padri Girolamini, a colossal work, full of expressive "lazzaroni"; also the frescoes of the Triumph of Judith at San Martino , and those in the Tesoro della Certosa, including the subject of Moses and the Brazen Serpent; and the cupola paintings in the Church of Santa Brigida, which contains the artist's own tomb. Other superior examples are the Judgment of Paris in the Berlin Museum, and Christ with the Doctors in the Temple, in the Corsini Gallery of Rome. In later years, he painted influential frescoes for the Cappella Corsini, the Palazzo Medici-Riccardi and other works.
As a young man he engraved works with considerable skill some of his own paintings, such as the Slaughter of the Priests of Baal. He also painted much on the crystal borderings of looking-glasses, cabinets and others seen in many Italian palaces, and was, in this form of art, the master of Pietro Garofalo.
His best pupil in painting was Paolo de Matteis. However, his influence, like his travels and career, were broad and prolific. For example, he is said to have influenced in Venice, Giovan Battista Langetti, Giovanni Coli, and Filippo Gherardi . Other pupils include Juan Antonio Boujas, Nunzio Ferraiuoli (Nunzio degli Afflitti), Ansel Fiammingo (il Franceschitto), Giovanni Battista Lama, Andrea Miglionico, Giuseppe Simonelli, Andrea Vicenti, Andrea Viso, Ferrante Amendola, Pedro de Calabria, Matteo Paccelli, Francisco Tramulles, Nicolo Maria Rossi, and Anniello Rossi. Luca Giordano died in Naples in 1705.