The common hawk-cuckoo is a medium- to large-sized cuckoo, about the size of a pigeon (ca. 34 cm). The plumage is ashy grey above; whitish below, cross-barred with brown. The tail is broadly barred. The sexes are alike. They have a distinctive yellow eye ring. Subadults have the breast streaked, similar to the immature shikra, and there are large brown chevron marks on the belly. At first glance they can be mistaken for a hawk. When flying they use a flap and glide style that resembles that of sparrowhawks (especially the shikra) and flying upwards and landing on a perch they shake their tails from side to side. Many small birds and squirrels raise the alarm just as they would in the presence of a hawk. The sexes are alike but males tend to be larger.