A missing elderly Chinese grandmother has been found more than 16 hours after being dropped by police at a Monash Freeway exit.

The 80-year-old woman, who does not speak any English, was reported missing by her family on Wednesday afternoon.

But police had already found Shifen Zhu walking along the Monash Freeway in the morning.

A police media spokeswoman said a Highway Patrol unit came across the woman walking along the freeway about 7.30am.