[4] As of October 2016[update], all Saikyo Line 205 series sets have been removed from service.

Before the Saikyo Line, there were several attempts to improve commuter rail service between Saitama and Tokyo.

One of the earliest, the Tokyo-Ōmiya Electric Railway (東京大宮電気鉄道, Tōkyō-Ōmiya Denki Tetsudō), was founded in 1928 but went bankrupt shortly thereafter due to rising land values in the area.

Later, in 1968, the Tokyo Metropolitan Board of Transportation proposed to run the new Toei Mita Line to central Ōmiya.

Development of the Saikyo Line began as a Japanese National Railways effort to quell unrest in Saitama regarding the expansion of the Tohoku and Joetsu Shinkansen.

During the mid-1970s, local protesters staged sit-ins, demonstrations, and administrative actions to impede the building of the new high-speed lines north of Tokyo.

JNR reached a settlement with the activists under which it would build a commuter line to serve these local communities, while being allowed to continue extending the Shinkansen.

However, even after names were assigned, passengers complained that each station looked just like the next due to their identical construction.

[3] The Saikyo Line has had a particularly severe problem of overcrowding during peak periods, especially during weekday mornings.

Problems resulting from overcrowding have included a higher incidence of groping, as well as delays in train schedule caused by longer time taken at each station to pick up and drop off passengers.