It replaced the previous Noctambus service on the night of 20/21 September 2005, providing for a larger number of lines than before and claiming to be better adapted to night-time transport needs.

In place of the previous hub-and-spoke scheme in which all buses terminated at and departed from the heart of Paris at Châtelet , Noctilien's new service includes buses operating between banlieues (the communes surrounding Paris proper) as well as outbound lines running from Paris' four main railway stations: Gare de l'Est, Gare de Lyon, Gare Montparnasse and Gare Saint-Lazare.

In addition, these four stations are also connected to each other by a regular night bus service.

Noctilien operates 52 bus lines over the whole of Paris and the Île-de-France region from around 12:30 a.m. when the rail network and the regular daytime bus service ends, until around 05:30 the next morning when they resume service.

[2] It is made up of: Like Transilien, the name "Noctilien" is formed by analogy with "Francilien" — the French demonym for residents of Île-de-France.