The White-thighed Swallow flies near the canopy above humid Amazonian forest. The appearance and range described here are those documented for subspecies griseiventris.
Its back and rump are bluish gray and its underparts are sooty gray. White tufts on the thighs can be difficult to see while it is flying.
It flies near the canopy above humid Amazonian forest and Andean foothills. The species-level account describes it as insectivorous and nonmigratory.
An extinction-risk assessment has not been added yet.