Fourteen people were in the hotel in Kroev when one storey of the building collapsed late on Tuesday.
Five were able to get out of the building unhurt, but another nine were trapped, police said.
By early Wednesday, emergency services had established that one person was dead, but had not yet been able to recover the body.
They were in contact with some of the eight people believed still to be in the building, some of whom were seriously injured, police said.
There was no immediate word on what caused the collapse or on the identity of the people affected.
Police said it was "an extremely demanding deployment, because emergency personnel can only enter the building with the greatest caution".
They said that some 250 emergency workers, including drone specialists, were at the scene, as well as rescue dogs.
Kroev is on a picturesque section of the river Moselle near the larger resort town of Traben-Trarbach, and has about 2200 inhabitants.