This species is found from the central Indo-Pacific area to the eastern Pacific coast, Hawaii included.

[3] Acanthurus nigricans was first formally described by Linnaeus in the 10th edition of the Systema Naturae published in 1758 with the type locality given as the Red Sea but it is actually thought to be Indonesia.

[2] The overall colour is bluish-black or black broken by a large patch of white below the eye.

In the Pacific Ocean it is more widespread and is found from the Ryukyu Islands of southern Japan south to the Great Barrier Reef and east across the Pacific to the eastern coasts of Central and South American between the Gulf of California and Ecuador.

[1] It is a benthopelagic fish with the adults being found at depths from the surface down to 67 m (220 ft) over hard substrates in clear waters in lagoons and over seaward reefs.