The short-nosed echidna is the smaller of the two echidna species. Body length can be up to 530 mm, with a tail about 90 mm long. Spines, which are specialized hairs covering most of the body, are large, hollow and thin walled, measuring up to 60 mm in length.
Spines are usually yellow with black tips, but can be entirely yellow.
Underneath the spines, short-nosed echidnas are covered with dark brown or black body hair, although in one subspecies, the hair covers the spines almost completely. The head is small and often has the appearance of having no neck. The tail is short, stubby, and naked underneath. The snout is long and slender and about half the head length. The feet have five digits with flat claws used for digging.