Together with his friend Achille Vianelli, Gigante was one of the principal artists of the School of Posillipo. He was introduced to painting by his father Gaetano Gigante, a decorator and landscape painter. Giacinto's brothers Achille Gigante and Ercole Gigante also became landscape artists. Giacinto trained in the style of Jacob Philipp Hackert and was influenced by the practice of technical drawing carried out at the Neapolitan Reale Ufficio Topografico, where he was employed in 1820. Also in 1820, however, he came to know the German painter Jakob Wilhelm Huber who, along with a large colony of foreign painters in Naples, worked in the classical and picturesque landscape tradition. Huber's picturesque style was based on perspective, and from him Gigante learnt both watercolour technique and the use of the camera lucida. In 1821, at Huber's studio, he met the Dutch painter Anton Sminck Pitloo, who became his teacher for a few years and who directed him towards painting directly from nature in a Romantic spirit. In the 1820's Giacinto Gigante enrolled the Reale Istituto di Belle Arti in Naples. Gigante did not fit in well with the life of the Istituto, however, and left early, although later being nominated honorary professor there. With the outburst of the revolutionary movements in 1848 Gigante left Naples and moved to Sorrento. Back in Naples, he became teacher of drawing in the Royal Court, until 1855.