Male blue-winged teal have a striking appearance with a gray-blue head marked by a prominent white crescent between the eye and bill. Their bodies are a cinnamon-brown with darker speckles, and they have a black rear end with a white patch on the flank. In flight, they display a pale blue patch on the upper wing with a white border and an iridescent green trailing edge. Female blue-winged teal are more uniformly brown, with a mottled pattern and a small white area near the base of the bill. They also have the distinctive pale blue wing patch in flight.

Male (Drake):
• Head: Gray-blue with a prominent white crescent between the eye and bill.
• Body: Cinnamon-brown with dark speckles.
• Rear: Black with a white patch on the flank.
• Wings: Pale blue upper wing patch, white border, iridescent green trailing edge.
• Call: A high-pitched whistle.

Female (Hen):
• Head: Mottled brown with a small white area at the base of the bill.
• Body: Mottled brown overall, darker eye line.
• Wings: Pale blue upper wing patch, white border, iridescent green trailing edge.
• Call: A loud, evenly spaced series of "quacks".