It consists of some 26 languages covering the Eastern Solomon Islands, from the tip of Santa Isabel to Makira.

It is defined by the merger of Proto-Oceanic *l and *R. The fact that there is little diversity amongst these languages, compared to groups of similar size in Melanesia, suggests that they dispersed in the relatively recent past.

[1] Bugotu, Gela and Lengo are three of the most conservative languages out of all of them.

According to Lynch, Ross, & Crowley (2002), the structure of the family is as follows:[2] Basic vocabulary in many Southeast Solomonic languages is somewhat conservative, unlike Northwest Solomonic forms, many of which have no Proto-Oceanic cognates.

[3] Below, Lengo and Arosi are compared with three Northwest Solomonic languages.