The southern terminus of State Route 218 is at a T-intersection with State Route 217 approximately 5 miles (8.0 km) northwest of Athalia.

Its northern terminus is at a T-intersection with State Route 7 about 2 miles (3.2 km) south of Gallipolis.

State Route 218 travels through portions of Lawrence and Gallia.

There are no segments of this state route that are incorporated within the National Highway System.

[3][4] Two years later, the southern end of the highway was realigned.