For its entire length, Iowa 191 closely parallels Mosquito Creek and the Bayard Subdivison of the BNSF Railway.

Iowa Highway 191 begins at exit 28 of Interstate 880 (I-880) north of Neola in Pottawattamie County.

Five miles (8.0 km) north of the county line, Iowa 191 enters the small town of Persia.

It enters Earling on the southwest side of town and ends at an intersection with Iowa Highway 37 and Shelby County Road M16.

[6] In 2002, the portion south of Interstate 680 (now I-880) was identified as a local service highway and was turned over to Pottawattamie County on July 1, 2003.