The church of Sant’Ignazio had remained unfinished with bare ceilings even after its consecration in 1642. Disputes with the original donors, the Ludovisi, had prevented the completion of the planned dome. Pozzo proposed to resolve this by creating the illusion of a dome, when viewed from inside, by painting on canvas. It was impressive to viewers, but controversial; some feared the canvas would soon darken.

On 25 December 1665, he entered the Jesuit Order as a lay brother. In 1668, he was assigned to the Casa Professa of San Fidele in Milan, where his festival decorations in honour of Francis Borgia recently canonised (1671) met general approval. He continued artistic training in Genoa and Venice. His early paintings attest the influence of the Lombard School: rich colour, graphic chiaroscuro. When he painted in Genoa the Life of Jesus for the Congregazione de’ Mercanti, he was undoubtedly inspired by Peter Paul Rubens.

Pozzo’s artistic activity was related to the Jesuit Order’s enormous artistic needs; many Jesuit churches had been built in recent decades and were devoid of painted decoration. He was frequently employed by the Jesuits to decorate churches and buildings such as their churches of Modena, Bologna and Arezzo. In 1676, he decorated the interior of San Francis Xavier church in Mondovì. In this church one can already see his later illusionistic techniques: fake gilding, bronze-coloured statues, marbled columns and a trompe-l’œil dome on a flat ceiling, peopled with foreshortened figures in architectural settings. This was his first large fresco.

In 1681, Pozzo was called to Rome by Giovanni Paolo Oliva, Superior General of the Jesuits. Among others, Pozzo worked for Livio Odescalchi, the powerful nephew of the pope, Innocent XI. Initially he was used as a stage designer for biblical pageants, but his illusionistic paintings in perspective for these stages soon gave him a reputation as a virtuoso in wall and ceiling decorations.

Meanwhile he continued painting frescoes and illusory domes in Turin, Mondovì, Modena, Montepulciano and Arezzo. In 1681 he was asked by Cosimo III de’ Medici, Grand Duke of Tuscany to paint his self-portrait for the ducal collection (now in the Uffizi in Florence). This oil on canvas has become a most original self-portrait. It shows the painter in a diagonal pose, showing with his right index finger his illusionist easel painting (a trompe-l’œil dome, perhaps of the Badia church in Arezzo) while his left hand rests on three books (probably alluding to his not-yet published treatises on perspective). The painting was sent to the duke in 1688. He also painted scenes from the life of St Stanislaus Kostka in the saint’s rooms of the Jesuit novitiate of Sant’Andrea al Quirinale in Rome.

In 1694 Andrea Pozzo had explained his illusory techniques in a letter to Anton Florian, Prince of Liechtenstein and ambassador of Emperor Leopold I to the Papal Court in Rome. Recommended by Prince Liechtenstein to the emperor, Andrea Pozzo, on the invitation of Leopold I, moved in 1702 (1703?) to Vienna. There he worked for the sovereign, the court, Prince Johann Adam von Liechtenstein, and various religious orders and churches, such as the frescoes and the trompe-l’œil dome in the Jesuit Church. Some of his tasks were of a decorative, occasional character (church and theatre scenery), and these were soon destroyed.

In 1695 he was given the prestigious commission, after winning a competition against Sebastiano Cipriani and Giovanni Battista Origone, for an altar in the St. Ignatius chapel in the left transept of the Church of the Gesù. This grandiose altar above the tomb of the saint, built with rare marbles and precious metals, shows the Trinity, while four lapis lazuli columns (these are now copies) enclose the colossal statue of the saint by Pierre Legros. It was the coordinated work of more than 100 sculptors and craftsmen, among them Pierre Legros, Bernardino Ludovisi, Il Lorenzone and Jean-Baptiste Théodon. Andrea Pozzo also designed the altar in the Chapel of St Francesco Borgia in the same church.

In 1697 he was asked to build similar Baroque altars with scenes from the life of St Ignatius in the apse of the Sant’Ignazio church in Rome. These altars house the relics of St. Aloysius Gonzaga and of St. John Berchmans.

Between 1701 and 1702, Pozzo designed the Jesuit churches of San Bernardo and Chiesa del Gesù in Montepulciano, but his plans for the last church were only partly realized.

Pozzo died in Vienna in 1709 at a moment when he intended to return to Italy to design a new Jesuit church in Venice. He was buried with great honours in one of his best realisations, the Jesuit church in Vienna. Agostino Collaceroni was also a pupil.

In Turin (1678) Pozzo painted the ceiling of the Jesuit church of SS. Martiri. The frescoes gradually deteriorated through water infiltration. They were replaced in 1844 by new paintings by Luigi Vacca. Only fragments of the original frescoes survive.