The northern subspecies, H. d. marwitzi is darker and smaller than nominate H. d. dimidiata, but the differences are small, and the species may be monotypic.

It is partially migratory with many birds from the southwest of South Africa wintering further north.

The pearl-breasted swallow feeds mainly on flying insects, with a fast direct flight.

It builds a bowl-shaped mud nest reinforced with grass or hair and with a soft lining.

The nest is built in natural cavities or man-made structures such as buildings, culverts and shafts, but its preference for isolated and abandoned buildings means that this species has not benefited from artificial sites to the same extent as, for example, the greater or lesser striped swallows.