Matawan Creek's main flow begins as Bakers Brook in Marlboro Township, Monmouth County, north of the intersection of Tennent and Woolleytown Roads.

Below the dam at Ravine Drive Matawan Creek becomes a tidal estuary, meandering through a salt marsh to its mouth.

From Route 35 to the mouth Matawan Creek forms the boundary between Aberdeen Township and Keyport Borough.

There are no further bridges downstream of County Route 6 and Matawan Creek empties into Keyport Harbor, an arm of Raritan Bay.

A shark killed 11-year-old Lester Stillwell and his 24-year-old would-be rescuer Stanley Fisher and severely injured 14-year-old Joseph Dunn later that same day.