The double-lined fusilier was first formally described as Caesio digramma in 1865 by the Dutch ichthyologist Pieter Bleeker with the type locality given as Ambon Island in Indonesia.

[3] In his 1987 review of the Caesionidae, Kent E. Carpenter placed this species within the subgenus Pisinnicaesio.

[4] The specific name digramma means 'two lined', a reference to the two yellow stripes on each side of the body, one on its back and one on its flanks.

[5] The double-lined fusilier has a fusiform and elongated body which is moderately laterally compressed.

The more ventral yellow stripe is mainly underneath the lateral line, apart from the portion on the caudal peduncle.

This is when up to 15 sneaker males join in as it is now that the initial pair release eggs and sperm while belly-to-belly at the surface.