[2] The blue-and-white swallow was first formally described as Hirundo cyanoleuca by the French ornithologist Louis Pierre Vieillot in 1817, based on a specimen he believed to be from Paraguay.

The migratory southern race N. c. patagonica is larger, 13.5 cm (5.3 in), has paler underwings, and white basal undertail coverts.

The blue-and-white swallow subsists primarily on a diet of insects, caught in the air; they have been seen to gather where termites swarm.

[7] The blue-and-white swallow's shallow straw nest is built by both adults in a wide range of natural or man-made cavities include tree holes, rock crevices and bridges.

[7] This common and popular species has benefited greatly from deforestation and human settlement which have increased the amount of suitable habitat and food.