The Optimus G Pro smartphone features a 5.5-inch screen that packs over 2 million pixels, or twice as many as smartphones with HD screens.
The new Android-powered phone sports other upgrades including a camera that can shoot full HD videos and photographs.
The South Korean company, Sony Corp., HTC Corp. and other phone manufacturers are trying to make high-resolution screens a key feature in their new smartphones this year.
Full HD screens are more common in televisions but smartphone makers began to embrace them this year amid cutthroat competition. One in every two smartphones is made by Samsung Electronics Co. or Apple Inc., creating a hardscrabble fight among the second-tier of makers.
LG executives said their current goal is elevating the reputation of the Optimus brand after turning around the company's mobile communications business following years of losses.
The Optimus G Pro will sell for 968,000 won (US$894) in South Korea without a mobile carrier contract.
The model will be on display at the annual mobile fair in Barcelona, Spain kicking off next week.
Once the world's No. 3 mobile phone maker, LG was the fifth-largest mobile phone maker by shipments in 2012 after Samsung, Nokia Corp., Apple and ZTE Corp., according to market research firm IDC.