Respiratory burst, enzymatic degranulation and bacterial killing were investigated on peripheral blood polymorphonuclear leukocytes (polymorphonuclear leukocytes) incubated with a pool of salivary fluids elicited from healthy donors. Low saliva concentrations primed polymorphonuclear leukocytes for enhancement of O2 consumption, O2- and beta-glucuronidase release and Staphylococcus aureus killing. Whole saliva, on the contrary, depressed all tested phagocytic activities.