Olive (Olea europaea) leaves have been used for various folk medicines for over a thousand years (Gucci et al., 1997) and are becoming very popular as a complementary medicine, commonly recommended for upper respiratory tract infections. In order to investigate the anti-microbial properties of olive leaf extracts, we used two commercially available products , a laboratory- produced extract and a solution of oleuropein, believed to be an active ingredient. Various species of Staphylococci were tested for susceptibility to the extracts, as S. aureus has been identified as a major cause of chronic bacterial sinusitis (Feazel, et al., 2012) and previous studies have shown that S. aureus is sensitive to olive leaf extract (Sudjana et al., 2009) . Strains tested included S. aureus (MRSA) ATCC 43300, S. aureus ATCC 25923, S. aureus ATCC 29213, S. aureus ATCC 6538P (NCTC 7447), S. auricularis, S. capitis, S. epidermidis ATCC 14990, S. epidermidis ATCC 35984, S. haemolyticus, S. hominis , S. intermedius ATCC 27335, S. saprophyticus ATCC 15305 and clinical isolates: S. aureus 82 and S. aureus (MRSA) 372, as well as 15 recent clinical isolates. Strains were also tested against a 30 µg disc of cefoxitin. Results indicated all of the S.aureus strains were inhibited by the laboratory extract but variable results were obtained for the non- S. aureus species. Clinical isolates of S. saprophyticus were generally more resistant than other species. Hence olive leaf extract has significant activity against S. aureus, including MRSA, but variable activity for other staphylococcal species.