The line runs west along the Ima River from Yukuhashi to Tagawa, all within Fukuoka Prefecture.

It was an important railway line to transport coal between the Chikuhō coal mine with Kanda Port (苅田港) in Kanda, north of Yukuhashi.

[1] Ridership suffered with the decline and closure of the Chikuhō coal mine.

Therefore, JR Kyushu, the successor of Japanese Government Railway, privatized and transferred the Ita Line, Itoda Line, and Tagawa Line to the newly founded Heisei Chikuhō Railway in 1997.

[2] The Tagawa Line runs through many historical sites, including the Second Issaka Tunnel (第二石坂トンネル), the oldest railway tunnel in Japan, and the Uchida Triple-Arch Bridge (内田三連橋梁), an old brick arch bridge.