Deputies responded to a reported home invasion in the 400 block of Porter Lane north of San Jose at about 8:40 a.m., according to the sheriff's office.
Investigators said a man posed as a pest control worker pretending to take soil samples and forced his way into the home of an elderly woman and assaulted her.
The suspect stole several pieces of jewelry and fled the area in a white cargo van.
The victim was taken to a hospital to be treated for injuries that were not expected to be life threatening.
The suspect was described as a Hispanic man around 5 feet 5 inches tall, according to the sheriff's office. He was wearing dark clothing during the attack.
Anyone who might have information regarding the attack is asked to contact Santa Clara County Sheriff Sgt. Ryan Elder or Detective Julian Quinonez at (408) 808-4500.