Mupirocin and amoxicillin-clavulanate were synergistic against 9 of 49 (18%) strains of methicillin-resistant and methicillin-susceptible Staphylococcus aureus and coagulase-negative staphylococci (CNS). A pattern of enhanced killing was also found using time-kill studies. Time-kill assays were more discriminatory than chequerboard titration assays in demonstrating synergy. These results suggest that combinations of amoxicillin-clavulanate and mupirocin may have therapeutic benefits in prophylaxis against staphylococcal infections. (C) 2004 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.