This is the largest Libyan study to date to investigate the prevalence and antimicrobial susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) among health care workers in Tripoli, Libya. A total of 569 doctors and nurses from 4 main hospitals were screened for MRSA with specimens collected from the anterior nares. Isolates from 109 of the 569 subjects (19%) were confirmed as MRSA by polymerase chain reaction assay; the majority (98/109) were from a general hospital. Antimicrobial resistance patterns tested by disk diffusion were as follows: erythromycin (74%), ciprofloxacin (77%), clindamycin (20%), trimethoprim/sulfamethoxazole (50%), quinuprisin/dalfopristin (19%), vancomycin (12%) and mupirocin (5%). Eighteen isolates exhibited macrolide-lincosamide-streptogramin B resistance (MLSB): 6 were MLSBi and 12 were MLSBc. The results provide evidence that Libyan health care workers could serve as MRSA carriers and play a role in the dissemination of MRSA to the public and other workers.