There are five accepted species of kiwi (one of which has four sub-species), plus one to be formally described.
- The largest species is the Great Spotted Kiwi or Roroa, Apteryx haastii, which stands about 45 cm (18 in) high and weighs about 3.3 kg (7.3 lb). (Males about 2.4 kg (5.3 lb)) It has grey-brown plumage with lighter bands. The female lays just one egg, with both sexes incubating. Population is estimated to be over 20,000, distributed through the more mountainous parts of northwest Nelson, the northern West Coast, and the Southern Alps.
- The very small Little Spotted Kiwi, Apteryx owenii is unable to withstand predation by introduced pigs, stoats and cats and is extinct on the mainland because of these reasons. About 1350 remain on Kapiti Island and it has been introduced to other predator-free islands and appears to be becoming established with about 50 'Little Spots' on each island. A docile bird the size of a bantam, it stands 25 cm (9.8 in) high and the female weighs 1.3 kg (2.9 lb). She lays one egg which is incubated by the male.
- The Rowi, also known as the Okarito Brown Kiwi or Apteryx rowi, is a recently identified species, slightly smaller, with a greyish tinge to the plumage and sometimes white facial feathers. Females lay as many as three eggs in a season, each one in a different nest. Male and female both incubate. Distribution of these kiwi are limited to a small area on the west coast of the South Island of New Zealand, however studies of ancient DNA have revealed that in prehuman times it was far more widespread up the west coast of the South Island and was present in the lower half of the North Island where it was the only kiwi species detected. 
- The Tokoeka, Apteryx australis,
relatively common species of kiwi known from south and west parts of
South Island that occurs at most elevations. It is approximately the
size of the Great Spotted Kiwi and is similar in appearance to the Brown Kiwi
but its plumage is lighter in colour. Ancient DNA studies have shown
that in prehuman times the distribution of this species included the
east coast of the South Island. There are several subspecies of the Tokoeka recognised:
- The Stewart Island Tokoeka, Apteryx australis lawryi, is a subspecies of Tokoeka from Stewart Island.
- The Northern Fiordland Tokoeka ( Apteryx australis ?) and Southern Fiordland Tokoeka (Apteryx australis ?) live in the remote southwest part of South Island known as Fiordland. These sub-species of Tokoeka are relatively common and are nearly 40 cm (16 in) tall.
- The Haast Tokoeka, Apteryx australis ?, is the rarest subspecies of kiwi with only about 300 individuals. It was identified as a distinct form in 1993. It only occurs in a restricted area in South Island's Haast Range at an altitude of 1,500 m (4,900 ft). This form is distinguished by a more strongly downcurved bill and more rufous plumage.
- The North Island Brown Kiwi, Apteryx mantelli or Apteryx australis
before 2000 (and still in some sources), is widespread in the northern
two-thirds of the North Island and, with about 35,000 remaining, is the
most common kiwi. Females stand about 40 cm (16 in) high and weigh
about 2.8 kg (6.2 lb), the males about 2.2 kg (4.9 lb). The North
Island Brown has demonstrated a remarkable resilience: it adapts to a
wide range of habitats, even non-native forests and some farmland. The
plumage is streaky red-brown and spiky. The female usually lays two
eggs, which are incubated by
Analysis of mitochondrial DNA, ecology, behaviour, morphology, geographic distribution and parasites of the North Island Brown Kiwi has led scientists to propose that the Brown Kiwi is three distinct species. The North Island Brown Kiwi; the Okarito Brown Kiwi (Rowi), whose distribution is restricted to a single site on the West Coast of the South Island of New Zealand; and a third distinct population of the North Island Brown Kiwi, the Southern Tokoeka, distributed in the in lowland forest to the north of Franz Josef glacier in the South Island and on Stewart Island/Rakiura, with a small population near Haast being another possibly distinct species, the Haast Tokoeka.