John Travolta had administered CPR (cardiopulmonary resuscitation) - an emergency medical procedure- on his son, who had been found dead at the actor's vacation home in the Old Bahama Bay resort community.
Jett, 16, who had a history of seizures arising from the rare condition Kawasaki Disease, had been found unconscious in the bathroom on January 2 by caretaker Jeff Katharain.
A hotel manager had been first to arrive on the scene, and along with Katharain, had tried to get the teenager's heart going with CPR.
The 54-year-old grieving father had come in shortly and from then on taken over, reports FoxNews.
Michael McDermott, the actor's corporate and commercial attorney, told TMZ, John for a "substantial period of time was performing CPR and continued that until EMT came and took over."
The teenager had been taken to Rand Memorial Hospital, Freeport, where he was pronounced dead, Police Superintendent Basil Rahming said in a statement.
It is yet to be determined if Jett fell to the floor as a result of a seizure or if he had a seizure after falling or slipping.
Obie Wilchcombe, a parliament member and former tourism minister in the Bahamas said two specialists would perform autopsy on Jett's body on January 5 to determine the cause of his death