The route turns east and crosses the East Branch Octoraro Creek into West Sadsbury Township in Chester County, heading southeast along Valley Avenue. The road curves south and passes under the Enola Low Grade Trail before making a sharp turn to the east into the borough of Atglen. PA 372 follows Valley Avenue through residential areas before turning south onto Main Street in the commercial center of the borough. The route passes homes before it turns east onto Lower Valley Road and passes commercial establishments, reaching a junction with PA 41. A short distance past this intersection, PA 372 crosses back into West Sadsbury Township and heads through farmland with some industrial buildings and homes. The route turns north onto South Limestone Road and runs along the border between West Sadsbury Township and the borough of Parkesburg to the east before fully entering Parkesburg, passing between industrial areas to the west and residential neighborhoods to the east. PA 372 curves east and follows West First Avenue past homes, continuing into business areas further east. The route crosses PA 10 and becomes East First Avenue, passing homes.