Objective – An efficient initial antibiotic therapy for patients infected by methicillin resistant Staphylococcus aureus (MRSA) improves the health prognostic in term of morbidity and mortality. The authors wanted to assess the Servitex Staphylocoque MRSA test ®: a rapid (30 min) slide latex agglutination test used to determine methicillin resistance by detecting PBP 2a in Staphylococcus aureus. Method – Sixty five Staphylococcus aureus clinical isolates (53 heterogeneous methicillin resistant S. aureus, nine homogeneous methicillin resistant S. aureus, three methicillin susceptible strains), and two control strains (ATCC 25923, CIP 6525) were studied. These strains were tested by various methods: agar diffusion with 5 μg oxacillin disk tested both at 30°C on Mueller-Hinton medium and at 37°C and on Mueller-Hinton plus 4% NaCl; latex test Servitex MRSA ® tested with two inocula (5 and 10 cfu); and dot blot hybridization with the mecA probe. Results – The methods used to detect methicillin resistance were of similar sensitivity except for the latex test Servitex MRSA ® with a 5 cfu inoculum which detected resistance in only 87% of the cases. A 100% accuracy was restored if a 10 cfu inoculum was used for the latex test Servitex MRSA ®. Comments – Standardization of the initial inoculum appears to be necessary for the reliable detection of methicillin resistance by the latex test. In a clinical laboratory, the use of the latex test is thus restricted to very specific cases if results are to be obtained in less than 48 hours.