Although tonsillectomy and adenoidectomy are common surgical procedures, the effects of these operations on the immune system have not been thoroughly determined. Our data on neutrophil chemotaxic functions in a group of 17 patients with chronic tonsillitis and adenoid hypertrophy show that chronic tonsillitis and adenoid hypertrophy impair neutrophil chemotaxic functions and that there is a subsequent normalization of these values following tonsillectomy and adenoidectomy.