A robber remains at large after trying to steal a bag containing gold worth $94,000 from a motorist on Sydney's north shore, police say.

The 50-year-old motorist was dropping a woman passenger off on Thomas Street, Chatswood, just before 2pm on Sunday.

A man tried to steal $94,000 worth of gold from a 50-year-old on Sydney's north shore, police say. Credit:Phil Carrick

As she got out of the car, the robber got into the car and struck the driver on the face with a metal object.

As the victim started to drive away, the robber jumped out of the moving car and ran down the street with the bag of gold.