The settlement was established on Mandji Island in the delta of the Ogooué River by the French, who signed a treaty with the Orungu people in 1873.

It was used as a base for the expeditions of de Brazza into the interior, then in 1894 a customs post was set up, becoming the nucleus of a trading center that included Hatton & Cookson, John Holt, Woermann, Société du Haut-Ogooué, and Compagnie d'Exploitations Forestières Africaines.

The town is now known for its hotels and its nightlife, while attractions include the St Louis Church (built in 1927), a zoo, a casino, beaches and a golf course, as well as the wildlife in local swamps.

The western Atlantic seaside is scarcely populated, mainly due to the presence of strong winds and sea currents.

As is the case with other cities in Gabon, the authorities have not yet implemented house numbering in Port-Gentil, and the use of postal boxes is common.

The roads are paved in the inner city up to the outskirts of the new residential districts in N'Tchengue, where sandy paths with frequent potholes prevail.

Traffic jams are common in road junctions such as the Carrefour Tobia or Léon Mba, close to the downtown area.

Furthermore, the lack of local car spareparts manufacturers underscores the need to import such parts from as far as Europe, the increased price as well as the lengthy delivery duration penalize altogether the traffic.