Adult giant geckos can grow up to 300 mm in length. The tail length is equal to or slightly longer than the head and body length, and it is the largest kind of gecko. The back is brick gray, with orange and blue-gray spots densely covered, and the tail has dark and light rings; the ventral surface is gray-white with pink spots.

The giant gecko has a large head, slightly triangular shape, a flat dorsal and ventral trunk, and a small covering throughout the body Grain scales, interspersed with larger warty scales, arranged in longitudinal rows; ventral scales are larger and slightly hexagonal. The limbs are moderate in length, with flat fingers and toes with a single row of skin folds below them; except for the first fingers, all have small claws, with only webbed tracks between the fingers and toes. Males have more than 20 preanal holes. The snout scales do not meet the nostrils.