The inaugural flight departed for Santiago, Chile, at 2:45 p.m.
The Dreamliner is the world's first commercial plane made primarily of lightweight carbon composites, making it about 20 percent more fuel efficient than comparable commercial jetliners.
Inside the cabin, passengers will notice oversized windows that dim electronically, high-definition video screens at every seat and what is promised as a smoother flight.
"The carbon composite makes the airplane itself more flexible, so whenever you're going through turbulences, you will have a less bumpier ride," said Juan Camilo Caicedo of LAN Airlines. "You'll feel less noise, less stress."
According to the airline, the Dreamliner has a solution for jetlag.
"It pressurizes at a lower capacity of altitude, so actually you get more oxygen, and provides a better atmosphere, so you lower your dryness, dizziness and you get more oxygen, which improves the jetlag," Caicedo said.
In August, LAN Airlines was the first carrier in the Americas to receive the new 787. Boeing has received more than 800 orders for the 787.