Arothron nigropunctatus is a small sized fish which grows up to 33 cm length. Its body is oval shape, spherical et relatively elongated. The skin is not covered with scales. The fish has no pelvic fin and no lateral line.The dorsal fin and the anal fin are small, symmetric and located at the end of the body. Its snout is short with two pairs of nostrils and its mouth is terminal with four strong teeth. The background coloration is variable and can be grey, light brown, bluish, bluish dark, bright yellow, orangey yellow and also sometimes bi-color like bluish and yellow. Dark coloration occurs around the eyes and the mouth. The skin is strewed with dark blotches which vary in size and shape.