Fourteen people were in the hotel in in the winemaking town of Kroev when one storey of the building collapsed late on Tuesday.
Police said five were able to get out of the building unhurt but another nine were trapped.
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.
The people trapped included a child, who was unhurt and in contact with emergency workers.
Regional public broadcaster SWR said witnesses reported hearing a bang and seeing a large cloud of dust at the time of the collapse.
There was no immediate word on what caused the collapse.
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, and rescue dogs were at the scene.
Kroev is on a picturesque section of the river Moselle near the larger resort town of Traben-Trarbach, and has about 2200 inhabitants.