Kentucky Route 338 begins at Kentucky Route 20 in Northern Boone County. It goes though Burlington, Kentucky where it intersects with Kentucky Route 18. It then goes to a small town called Rabbit Hash, Kentucky where it intersects with Kentucky Route 536 and again with Route 18. After it leaves Rabbit Hash, it runs by Big Boone Lick State Park before intersecting with US 42 and US 127 near Union. It turns left onto US 42 and US 127, and then leaves the concurrency about mile north. Route 338 then travels to Richwood, were it has access to Interstate 75 and Interstate 71 it ends about 1/4 mile east of the interstate at US 25.