Using a modified Boyden chambers method, polymorphonuclear leucocyte (pmnl) random migration and chemotactic responsiveness were compared in 20 rheumatoid arthritis patients with that of 10 healthy controls receiving tenoxicam. Random migration and chemotaxis of neutrophils were examined before drug administration, following 2 hours and 7 days of drug administration and one week after the end of the 7-day-administration of this compound. There was no statistically significant difference between the chemotactic migration of neutrophils in healthy volunteers and patients with RA. The mean chemotactic value in patients with RA and healthy controls was significantly low at 2 hours after drug administration when compared with that before drug administration (p<0.01). The comparison of the decreases in mean chemotactic values in patients with RA and healthy controls showed no statistical difference. At the end of 7-day-administration, neutrophil chemotaxis was significantly decreased in patients with RA (p<0.01); however, in healthy controls it was decreased as well, but statistical difference could not be obtained. One week after drug withdrawal, neutrophil chemotaxis turned to baseline values in both groups. We suggest that tenoxicam is a potent inhibitor of neutrophil chemotaxis.