[3] Colostethus agilis is endemic to Colombia, where it is found in the western parts of the Cordillera Occidental at heights between 2,190 and 2,600 metres (7,190 and 8,530 ft) above sea level.

[2][3] Its range extends from La Serrania de los Paraguas southwards to the Munchique National Natural Park, and it inhabits the floors of moist forests and the streams that flow through them.

Scientists believe its range may include one other protected park: Parque Nacional Natural Farallones de Cali.

[1] The IUCN Red List of Threatened Species includes Colostethus agilis as endangered.

The main threats it faces are forestry activities, the conversion of woodland to agricultural uses (including illegal crops) and pollution of the streams in which it is believed to breed, the conversion of woodland to cattle grazing area, and mining operations.