Students had to be rescued from the multi-occupancy premises at Nine Tree Hill in Cotham after a fire in January 2012.
Landlord Garreth Wilson was found to have breached fire safety regulations and afterwards was handed a four-month suspended prison sentence and told to pay £10,000 costs.
But Bristol Crown Court heard today that, just five months after the blaze Avon Fire and Rescue Service checked the flats again and found there were still fire safety risks which had not been tackled.
Wilson, 62, of Beaufort Cottage in Clifton, pleaded guilty to an additional three breaches of fire safety law.
Judge Martin Picton activated three months of the previously suspended term and added another three months on top.
The judge told Wilson: "I just don't know how potent a warning someone has to have to behave differently as a landlord of multi-occupancy flats.
"People who rent properties are entitled to expect the appropriate level of care taken for their safety."
The judge ordered him to pay prosecution costs of £12,441.91
Sam Jones, prosecuting, said after the fire at the 11-room multi-occupancy premises in January 2012, Wilson was found to have breached fire safety law and handed a suspended jail term.
Five months later, as a result of information received, Avon Fire and Rescue Service inspected the flats again and identified a number of fire safety failures.