Pseudanthias parvirostris has a somewhat elongated, moderately compressed body which is around 3 times as long (in standard length as it is deep.

The males have a thickened upper lip which is a little pointed and can be moved up and down, although this is less marked in this species than in related Pseudanthias.

It has a moderately large, obliquely angled mouth in which the maxilla extends to the level of or beyond the rear edge of the eye.

Its range extends from Japan south as far as Australia, west to the Madives and east to the Solomon Islands.

They are usually found in small aggregations close to the bottom, where there are patch reefs on slopes dominated by sand or rubble.