Within the Ostia excavations, the Ostia Museum is located in the Casone del Sale, a Renaissance building linked to the exploitation of the salt pans by the papal government. Home to the museum since 1934, it saw a first partial expansion of the exhibition in 1952, and a significant rearrangement in 1962, which has remained virtually unchanged to this day.

The need to refurbish the museum arose from the twofold need to illustrate the history and context of the Roman city of Ostia through a completely new museum narrative compared to the past, and at the same time to restore and bring up to standard, also from the point of view of accessibility, the building, the Casone del Sale, dating back to the 16th century and formerly the seat of the Museo Ostiense. The museum has also been updated in terms of plant, lighting and technological equipment, as well as in terms of science and exhibition, in order to give the artefacts the right atmosphere and full enjoyment.

The museum itinerary is divided into 12 rooms; the museum narrative is divided into 7 major macro-themes: the origins and the republican age, imperial power, civic spaces, the people, religions and cults, the necropolises of the area, and forms of living.

At the entrance to the Museum, rooms I and II provide a multimedia introduction to the Museum; room III is dedicated to the origins of the city and the Republican age: among the works is the delicate terracotta statue from the sacellum of Isis, identified as Fortuna; the adjacent room IV is dedicated to the Republican sanctuary in Via della Foce, from which comes, among others, the bust of Asclepius, dating back to the 2nd century BC. C. and the relief of the haruspex Fulvius Salvis, made in the first decades of the 1st century BC.

Room V is dedicated to images of imperial power: the statue of Trajan from the Schola del Traiano, of Sabina as Ceres from the Decumanus, and of the so-called Maxentius are just some of the works depicting emperors or personalities belonging to imperial families; Room VI, dominated by the Statue of Winged Victory that once decorated the attic of Porta Romana, is dedicated to Civic Spaces and Public Monuments: in addition to the statue of Cartilius Poplicola, fragments of the Fasti Ostiensi, the dedicatory inscription on the Porta Romana and fragments of the frieze of the Forum basilica are exhibited here.

Room VII is dedicated to people: the portraits, grouped in the centre of the room, depict the faces of men and women of Ostian society, covering a chronological span from the middle of the 1st century BC to the second half of the 5th century AD.

The large room VIII is dedicated to religions and cults: in the centre stands the statue of Mithras Tauroctonus from the Mithraeum of the Baths of Mithras, a work by the Athenian artist Kriton.
Next, Rooms IX and X are dedicated to the necropolises of the area, while Room IX delves into the funerary contexts from the Necropolis of Porto on Isola Sacra: the statue of Iulia Procula from Tomb 106 and the Sarcophagus of the Muses with its trousseau are two works of the highest value and great artistic refinement.

After the cities of the dead, in Room XII, we finally enter the houses of the living. The forms of living are developed above all in the paintings that the Ostiense houses have yielded numerous, such as the frieze with representations of dwarves, from the Domus dei Bucrani. Finally, a small hallway, almost a cubiculum, is the space of the 'philosophers', among which the Herma of Themistocles from the House of Themistocles stands out.

The exhibition route is complemented by a multimedia apparatus that complements the traditional didactic tools: historical photographs and drawings preserved in the Ostiense archives show the main monuments and neighbourhoods of the city on touchscreens: a way to make a wealth of documentation accessible that would otherwise not usually be visible; in addition, in-depth videos are available through a sound shower system, with sound directed at the viewer so as not to disturb other visitors in the room.