It runs along two former sections of Highway 19 on Vancouver Island, within Nanaimo and between Craig's Crossing and Campbell River.

Highway 19A proceeds through the southern part of the city of Courtenay on Cliffe Avenue, then crosses the Courtenay River on one of only two road drawbridges on Vancouver Island (also known as the 17th street bridge), intersects with the main road into Comox, and travels along a bypass around the city centre.

This stretch of highway 19A through the main city of Courtenay is heavily congested.

The highway continues inland for 26 km (16 mi), through the communities of Grantham, Merville, Black Creek, and Oyster River before rejoining the coastline at the intersection with Oyster Garden Road.

From there, the highway hugs the coastline for 18 km (11 mi), entering the city of Campbell River, passing by the B.C.