Great Argus Pheasants have a diet consisting of a variety of food sources found on the forest floor, including fruits, seeds, and insects. They roost in trees at night and forage on the ground during the day.

Males and females of this species have notable differences. Males are sizable, weighing between 2 to 2.72 kg, with a length ranging from 160 to 200 cm. Their magnificent tails measure approximately 105 to 143 cm. Females resemble the males but lack the grand secondary wing feathers and long tail. Females weigh around 1.59 to 1.7 kg, with a length of 72 to 76 cm and a tail length of 30 to 36 cm.

Interestingly, unlike other Galliformes, the Great Argus lacks an oil gland, known as the uropygial gland.

During the breeding season, male Great Argus Pheasants create a designated area on the ground with a ring constructed from sticks and twigs. This serves as a stage for their elaborate courtship display. He has an amazingly loud contact call that echoes through the forest. As a female approaches, he struts back and forth, showing the patterns on his feathers. Then he opens his wings into a cone-like shape full of eye spots and other patterns. After successful courtship, the female will lay two eggs and incubate them alone.

The population of Great Argus Pheasants is declining due to various factors including hunting, trapping, logging, and climate events such as droughts.