The fire broke out near the Tondela municipality, which lies between the northern towns of Coimbra and Viseu, which were badly hit by a series of deadly wildfires in October.
Some of the more seriously wounded were airlifted to hospital by helicopter.
Tondela mayor Jose Antonio Jesus told RTP public television that the fire broke out when a wood-burning stove exploded as people gathered for an amateur card playing tournament.
The fire spread very rapidly but was finally controlled after an hour, the Tondela fire service said.
Civil protection chief Paulo Santos said: "Around 70 people were having dinner in the building when the fire broke out and we have a number of dead people as well as between 50 and 60 people injured."