Staphylococcus aureus superantigens and bacterial biofilms have been implicated in the development of chronic rhinosinusitis and nasal polyps. We conducted a study of 32 Lebanese patients-21 males and 11 females, aged 15 to 71 years (mean: 39)-to identify bacteria isolated from nasal polyps and to determine if these bacteria produced superantigens and biofilms. Polyps were surgically removed, homogenized, and subjected to bacteriologic studies. The presence or absence of S aureus enterotoxin A, B, C, and D (superantigen) genes was determined in all isolates by polymerase chain reaction. Biofilm production by coagulase-negative staphylococci and Pseudomonas aeruginosa was assessed by tissue culture plate assay. A total of 34 bacterial species/groups were isolated from the nasal polyps. Of these, only 3 (8.8%) were S aureus, and only 1 possessed an enterotoxin-coding gene (enterotoxin B). Moreover, of the 21 coagulase-negative staphylococci isolates that were found, none possessed the investigated genes, and only 1 had a strong biofilm-formation property. Our results could not confirm that S aureus enterotoxins (superantigens) or biofilm-producing bacteria play a role in the development of nasal polyps in the Lebanese group studied.