The southern terminus is in Pelham at the Massachusetts state line, where the road continues south as Massachusetts Route 38, which runs 27 miles (43 km) from Dracut to Somerville.

At Main Street, it begins to bend to the northeast, passing under a power line corridor, and then heads through a residential neighborhood.

It crosses into Salem, Rockingham County where the highway name changes to Lowell Road.

Through Salem, NH 38 crosses another residential neighborhood before it heads past more commercial properties.

The road passes under I-93 before it curves to the north to head along the west side of the Mall at Rockingham Park and its name changes to Pleasant Street.