Tanashi Station is served by the 47.5 km Seibu Shinjuku Line from Seibu-Shinjuku in Tokyo to Hon-Kawagoe in Saitama Prefecture.

Located between Seibu-Yagisawa and Hana-Koganei, it lies 17.6 km from the Seibu Shinjuku terminus.

[1] All trains except Limited express Koedo services and the Haijima Liner stop at Tanashi Station.

[2] In fiscal 2019, the station was the 11th busiest on the Seibu network with an average of 75,418 passengers daily.

The station is a frequent setting in the Japanese animated sitcom Atashin'chi, adjacent to the surrounding region that was formerly Tanashi.