The green-winged macaw can be readily identified from the scarlet macaw. While the breast of both birds are bright red, the upper-wing covert feathers of the green-winged macaw is mostly green but can occasionally sport a few yellow feathers above the band of green (as opposed to mostly yellow, or a strong mix of yellow and green in the scarlet macaw). In addition, the green-winged macaw has characteristic red lines around the eyes formed by rows of tiny feathers on the otherwise bare white skin patch; this is one of the biggest differences from a scarlet macaw to the casual viewer. Iridescent teal feathers are surrounded by red on the tail. If seen together, the green-winged macaw is clearly larger than the scarlet macaw as well.
The green-winged macaw generally mates for life. The female typically lays two or three eggs in a nest made in a hole in a tree. The female incubates the eggs for about 28 days, and the chicks fledge from the nest about 90 days after hatching.