The fire broke out just before 1 pm (05:00 GMT) on Tuesday in the eastern wing of the Beijing Changfeng Hospital, and was extinguished after about half an hour, according to Aljazeera.
All but three of those who died were patients, the source added.
Dozens of people were evacuated from the seven-story building as the flames took hold, with 39 people being treated for injuries sustained in the fire. Officials said three of them are in critical condition, and 18 in serious condition.
Initial investigations suggest the blaze was caused when flammable paint materials ignited during renovation work.
AMK/PR