In March 1855, Pasini set off through Egypt, Saudi Arabia, South Yemen and the Persian Gulf, finally arriving in Teheran, where he spent a year and a half. Not only were many of his trips around Persia made in the company of the shah, but the sovereign commissioned a number of paintings. Pasini returned in 1856, this time via the Black Sea and Constantinople. Once back in Paris, he began to send views of Persia, Arabia, Azerbaijan and Syria to the annual Salons. He was able to meet up with old Persian hands in Jules Laurens's studio, such as the artists Prince Soltykoff, Eugene Flandin and Colonel F. Colombari. His high expectations fulfilled after this adventure, Pasini continued to travel: Constantinople in 1868-69, Asia Minor, Syria and Lebanon in 1873, frequent visits to Venice, and two journeys to Spain, one in the company of Jean-Léon Géröme and Albert Aublet. After dividing the rest of his time between Paris and his villa in Cavoretto, near Turin, he finally settled down in Italy to concentrate on agriculture as well as painting.
Pasini was probably the best-known Orientalist artist of foreign origin in France. He found a ready sale for his canvases through the Parisian dealer Goupil, and had a faithful following of American visitors to the Salon; many examples of his work are now to be found in American and Canadian museums. He sent paintings on show to Florence and, more particularly, to his city of adoption, Turin. At the national exhibition in Turin in 1880, he received a diploma, while at the one in 1898, he exhibited three hundred studies in a room specially reserved for him. He gave many of these to the city. Other examples of his work are in museums in Amsterdam, Florence, Montreal, Sydney, Nantes and Mulhouse.
Like Fromentin, with whom he was often compared, Pasini was struck by the delicacy of the light in the East. His treatment of the play between shadow and sun and his quasiphotographic representation of architecture and figures are a world apart from the imaginary exoticism of earlier Orientalist paintings. He excelled in group compositions of horses, their shiny rumps towards the spectator, held by simple soldiers who mix with merchants and passers-by. Small details are typical: dogs basking in the sun, a tree throwing its shadow onto a nearby wall.
Pasini was particularly careful to study precise details of tilework and inscriptions, and in very many paintings, such as Halte de cavaliers syriens la porte d'un bazar (Syrian Horsemen Paused at the Entrance to a Bazaar), Cavaliers circassiens attendant leur chef (Circassian Horsemen Awaiting their Leader), La cour d'un khan un jour de marché (Khan Courtyard on a Market Day) and Marché aux chevaux, (Horse Market), the architecture has an important place. Other pictures, of great charm, are of Turkish women. In veiled clusters, picnicking by a kiosk, relaxing in the garden of a country house, or holding parasols as they stroll through a busy street, they are reminiscent of the women found in the Turkish school of painting led by Osman Hamdi Bey. Silent, respectable, modest, they are a far cry from the slave girls, dancers and femmes fatales who served, in so many Orientalist paintings, to titillate the imagination of the Western public.