Chemiluminescence activity of granulocytes in phagocytosis of zymosan and Escherichia coli and their responses to chemoattractant N-formylmethionyl-leucyl-phenylalanine (FMLP) were evaluated in 13 major blunt trauma patients (Injury Severity Score 31 ± 6) and their plasma fibronectin concentrations were measured. Chemiluminescence responses to zymosan and E. coli were at control levels immediately after injury and a week thereafter, but responses to FMLP were increased compared to the controls (p < 0.05). Plasma fibronectin concentrations were depressed on the day after trauma (p < 0.001) but increased to control values over 1 week. The changes had no correlation with the patients’ recove