Known for most of its length as Jarratt Avenue, the state highway runs 1.48 miles (2.38 km) from SR 610 east to U.S. Route 301 (US 301) and SR 631 within Jarratt.

The state highway heads northeast as two-lane undivided Allen Road, which intersects a railroad spur that serves the adjacent Georgia-Pacific plant.

SR 139 turns southeast onto Jarrett Avenue, which passes through a residential area and crosses the rail spur again.

Shortly after crossing the Greensville–Sussex county line, the state highway has an at-grade crossing of CSX's North End Subdivision, then curves to the southeast at the intersection with SR 646 (South Halifax Avenue), only to curve back to the east at Henry Road.

SR 139 reaches its eastern terminus at a four-way intersection with US 301 (Blue Star Highway) and SR 631 (Henry Road) at the eastern town limit of Jarratt.