The phagocytic function of neutrophils has been studied in 50 Egyptians of both sexes and of various ages, suffering from burns of different depths and extents, and the results compared with data from 50 normal persons of similar sex and age. The nitro blue tetrazolium test (Gifford and Malawista, 1970), and the bacterial killing test (Quie et al., 1967), have been used during the first 24 hours, and then repeated at weekly intervals for 4 weeks. The phagocytic power showed no change during the study except in two patients with extensive burns during fatal septicaemia. The bactericidal capacity, and the formazan cell formation showed similar changes with a steady decrease from the first to the third weeks, followed by a rise during the fourth week. Similar changes were noticed in the serum albumin levels. The decline was more marked in burns of more than 50 per cent of the body surface area and during severe sepsis. Improvement coincided with healing.