The victims include five men and three women, who were being treated at the ICU ward of the COVID-19 designated Shrey Hospital in Navrangpura area of Ahmedabad, the official said.
Fire broke out around 3.30 am on Thursday, he said.
"Eight coronavirus patients admitted in the ICU ward of Shrey Hospital have died due to the fire, which has been doused," said an official of the Ahmedabad Fire Department.
The cause of the fire is not known yet, he said.
With 1,073 new coronavirus positive cases, Gujarat's COVID-19 tally reached 66,777 on Wednesday. The number of deceased has gone up to 2,557, an official said.