Aaron Gantz, 4, and Jacob Gantz, 6, were visiting their grand-mother in the Spann Hill community on Ky. 1275, said Forrest Hicks, Wayne County deputy coroner.
The children had been playing a video game in the living room while their father, Jason Gantz, was outside, according to Kentucky State Police.
A neighbor noticed the fire and called the Wayne County 911 dispatch. Both children were found in the kitchen near the back of the house, police said.
The boys were carried to the back yard, where neighbors and the father administered CPR until firefighters and emergency responders took over, said Steve Ferrell of the Monticello fire department.
The department received two calls about 3:30 p.m. and arrived at the scene at 3:43 p.m., Ferrell said.
The boys were transported to the Wayne County Hospital, where they were pronounced dead at 5:15 p.m., officials said.
The fire department contained the fire in the living room of the two-story house, Ferrell said. The house received mostly smoke damage.
Smoke inhalation might be the cause of death, Hicks said. The bodies were sent to the State Medical Examiner's Office in Frankfort for an autopsy to determine a cause of death.
Kentucky State Police said the cause of the fire has not been determined, but foul play is not suspected.