Muhammad Yasir sustained bullet injuries and was being treated at Mayo Hospital in Lahore.
"Yasir succumbed to his injuries while the condition of another injured policeman is critical," said Zahid Pervez, a doctor at the hospital.
Nine policemen were killed and as many injured when a group of 10 heavily armed militants attacked a building in the residential area of Ichra on Thursday.
The banned Tehrik-e-Taliban Pakistan had claimed the responsibility for the attack.
The policemen were all employees of the prison department of Kyber-Pakhtunkhwa province and had come to Lahore for a training course.
They were living in a private building rented by the prison department of Punjab province.
In a related development, police have arrested seven members of the banned Lashkar-e-Jhangvi and Sipah-e-Sahaba in connection with the attack, officials said.
"We are interrogating them in connection with the attack in Lahore. Though there has been no breakthrough as yet, our search operations are continuing across the province," a Punjab Police spokesperson said.