The station, on a four-track section, is served by local and rapid services (not including special rapid services and other fast trains) of the Chūō Main Line on weekdays.

The station uses a special train departure melody during the Koenji Awa Odori festival held in late August.

It is within walking distance of Shin-Kōenji Station on the Tokyo Metro Marunouchi Line.

The Number of Passengers on Kōenji as recorded by the East Japan Railway Company Trains in 2017-2022 was 14,618 (（単位　千人）).

[2] The original station building was destroyed in the bombing of Tokyo in 1945 and a permanent replacement was completed in 1952.