The company was founded in 1967 under President Carlos Lleras Restrepo to connect power stations and enable electricity transmission across Colombia.

Following Colombia's 1992 energy crisis, ISA underwent restructuring under new leadership, led by civil engineer Javier Gutiérrez.

The government issued decrees and laws between 1992 and 1994 allowing private sector participation in the electric industry through independent generators, separating it from network transport.

To support growth, ISA entered the Colombian Stock Exchange in 2001, raising funds for expansion.

[3] On August 20, 2021, Ecopetrol acquired a 51.4% controlling stake in the company, previously held by the Ministry of Finance and Public Credit, establishing a diversified energy conglomerate in South America.