The plane took off from Merida in the west of the country and was destined for the capital, Caracas.
The twin-engine aircraft was diverted because of poor weather, before losing contact with air traffic controllers.
There is no confirmation that it has crashed, but rescue teams are preparing to search the area near Merida for wreckage and any survivors.
Civil defence officials say operations will have to wait till daylight on Friday, because the rugged terrain makes it too difficult to search in the dark.
Merida is located in a mountainous region, 680 km (422 miles) southwest of Caracas.