PA 198 begins at the
Ohio border in
Beaver Township, where the road continues into that state as
SR 167. From the state line, the route heads east on two-lane undivided Pierpoint Road through a mix of farmland and woodland. PA 198 passes through Palmer before entering
Spring Township and becoming Atroskin Road. The route continues into the borough of
Conneautville and becomes Licking Street, passing homes. PA 198 turns northeast onto Mulberry Street and crosses
Conneaut Creek and the
Canadian National's
Bessemer Subdivision railroad line before coming to an intersection with
PA 18. At this point, PA 198 turns southeast to form a
concurrency with PA 18 on Main Street, passing through the commercial downtown prior to passing more residences. PA 198 splits from PA 18 by heading east on an unnamed road, crossing into
Summerhill Township. The road continues through a mix of farms and forests with a few homes, curving to the southeast and crossing
Rundelltown Creek west of Norrisville. In the community of Norrisville, the route enters
Hayfield Township and heads more to the east. In Littles Corners, PA 198 comes to a junction with
PA 98. The route continues through more rural areas, crossing the
Cussewago Creek and passing through Coons Corners prior to reaching an interchange with
I-79. A
park and ride lot is located within the southeast quadrant of this interchange. Past this interchange, PA 198 passes through a mix of farmland, woodland, and residences and turns north onto North Mead Road before turning east onto another unnamed road. The road runs through rural areas with some residential development prior to crossing the
French Creek into the borough of
Saegertown and coming to a
roundabout with
US 6/
US 19. Here, PA 198 turns south to form a concurrency with US 6/US 19 on Main Street, passing a mix of homes and businesses. In the southern part of town, PA 198 splits at a roundabout by heading east on South Street, passing under a
Western New York and Pennsylvania Railroad line. The route turns southeast and becomes unnamed, passing a mix of farmland and woodland with a few homes as it heads into
Woodcock Township. PA 198 turns south for a short concurrency with
PA 86 prior to continuing east through forested areas with some homes, passing to the north of Woodcock Creek Lake. The road turns to the southeast and continues into the borough of
Blooming Valley, where it becomes Saegertown Street. The route passes homes and turns south, coming to an intersection with
PA 77. Past here, PA 198 becomes Dickson Street and runs past more residences, leaving Blooming Valley for
East Mead Township. The road continues through areas of woods and farms with some residences, turning south and becoming the border between East Mead Township to the west and
Randolph Township to the east. The route turns east and fully enters Randolph Township, passing through more rural areas and turning south. PA 198 continues to the residential community of
Guys Mills, where it turns east and passes through the
Erie National Wildlife Refuge. The route turns south and passes through farmland, woodland, and homes prior to coming to its terminus at
PA 27. ==Major intersections==