The Rome–Naples high-speed railway line (which was largely opened on 19 December 2005) generally follows the same route.

It operated from a terminal at Napoli Porta Nolana, now used by the Circumvesuviana Railway.

A branch line was opened from Cancello to Nola in 1846 and extended to Sarno in 1856.

[5] The northern part of the line was opened between a station at Porta Maggiore (southwest of the modern Termini station) and Ciampino on 14 July 1856 as part of the Rome–Frascati line by the Società Pio Latina ("Latin Pius Railway"), a French company named in honour of Pope Pius IX, who had overturned the Vatican's previous opposition to innovations such as railways in the Papal States.

[6] In 1860 the Società Pio Latina and the Società Pio Centrale—the builder of the Rome–Civitavecchia railway, opened in 1859—combined to form the Società per le strade ferrate romane ("Roman Railway Company"), which then absorbed the Royal Neapolitan Railway Company.