Ramiro Ruiz Medrano, Interior Ministry spokesman for the region of Castilla y Leon, says three adults and three minors died from suspected smoke inhalation.
Three other grown-ups and two children were taken to a hospital with minor burns and respiratory complaints.
Ruiz Medrano says the fire broke out in the early hours today as the family slept.
The hotel is located in the town of Tordomar, 215 kilometres north of Madrid.