Murray River rainbowfish reach maximum body lengths of 11 cm, but the males are usually no larger than 8.5 cm, while the females usually only grow to 7 cm. The body is elongated, with a small head and large eyes. Murray River rainbowfish have two dorsal fins and a pointed anal fin, and the caudal (tail) fin is forked shallowly. The fins (excluding the caudal fin) are yellow with dark margins and orange or red markings.

 Murray River rainbowfish are colourful fish. Their sides are silvery-brown, and have a green or silver sheen. A blue stripe extends from the snout to the caudal fin. The other fins are yellow and marked with orange or red. In males, several orange stripes run laterally across the posterior half of the body. Males have red spots on the dorsal, anal and caudal fins, with a blackish margin when breeding. Females are less intensely coloured, lacking some of the brilliance and red stripes along the caudal peduncle.