Mecodema kokoromatua is a medium-bodied ground beetle endemic to Northland, New Zealand.

Its range is restricted to coastal forest behind the sand dunes and below the southern areas of the Ahipara Escarpment, Herekino, Northland, New Zealand.

Differs from other North Island Mecodema species due to having: Length 22–25 mm, pronotal width 4–4.5 mm, elytral width 5–5.5 mm.

Colour of entire body matte to glossy black, coxae may be dark reddish-brown.

[2] Restricted to sandy soils of the Pleistocene dune systems with coastal broadleaf forest of southwestern Ahipara District, Northland.