These fish reach a length of 3 to 4.5 cm. This barb species exhibits pronounced sexual dimorphism. Males are usually larger, their bodies are colored in yellow-pink tones, and a black spot is visible at the base of the tail. Their main distinguishing feature is a large, yellow dorsal fin with black speckles. During spawning, males look particularly impressive: they spread their dorsal fin, and their coloration becomes noticeably more intense. In contrast, females may seem less remarkable: they are smaller, have a silvery coloration with a dark spot near the tail, and a black and yellow stripe on the dorsal fin. Outwardly, the Oreichthys barb has much in common with a related species, the Cosuatis barb, under which name it is often mistakenly sold.