During the last few years, several studies have pointed out the imbalance of immune responses with advancing age, this accounting for the increased susceptibility of elderly individuals to life-threatening diseases. This review is focussed on the role of neutrophil respiratory burst in the age-associated decline of cytotoxicity towards invading microorganisms. Particular emphysys is given to extracellular matrix proteins, acting as physiologic regulators of oxidative activity, as well as to neutrophil cytoskeleton, whose dysfunction is likely to be involved in the agonist-related defect of the coupling between beta2-dependent adhesive and oxidative events occurring in the aging. The role of oxidative metabolism in the increased incidence of apoptotic phenomena observed in neutrophils of aged following cell stimulation is also discussed.