The rose-ringed parakeet is sexually dimorphic. The adult male has a red or black neck ring and the hen and immature birds of both sexes show little or no neck rings. Both sexes have a distinctive green colour.
Rose-ringed parakeets measure on average 40 cm (16 in) in length, including the tail feathers, a large portion of their total length. Their average single-wing length is about 15–17.5 cm (5.9–6.9 in). In the wild, this is a noisy species with an unmistakable squawk. Captive birds can be taught to speak. It is herbivorous and not migratory.