Police say the crash happened at 12:46 p.m. Friday on Route 29 in Upper Hanover Township.
Police said a northbound sport utility vehicle trying to make a left turn collided with a southbound car, sending it into the path of another northbound SUV.
Lehigh County Coroner Scott Grim said 73-year-old Theodore Hiriak and 69-year-old Maryann Hiriak were pronounced dead at Lehigh Valley Hospital about an hour later.
A passenger in the second SUV was treated at a hospital and released. The crash remains under investigation.