Background: Methicillin-resistant Staphylococcus aureus (MRSA) represents a serious causal agent in nosocomial infections that are becoming increasingly difficult to cure due to their emerging resistance. Therefore, it becomes essential to understand the epidemiology of MRSA where pulsed field gel electrophoresis (PFGE) is considered to be the gold standard for the this. Objectives: This study aimss to make genotyping for the nosocomial strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated form General Surgery Department of Tanta University Hospitals with tracing the source of infection as a guideline for infection control. Methodology: 159 different samples were collected from patients and 41 from suspected sources of infection. MRSA isolates were screened by Cefoxitin disk diffusion method then confirmed by detection of MecA gene by PCR. Phenotyping of the isolates was done by using the antibiogram while genotyping was done by using pulsed field gel electrophoresis (PFGE). Results: MRSA isolates were found in 60 patients and 5 health care workers (HCWs). Genotyping revealed 26 patterns (A - N & a - l) where type (A) was the most predominant. Isolates which had identical genotypes had different antiograms .Each ward revealed infection with muliple strains indicating multiple sources of infection while certain strains were found in multiple patients and multiple wards. Genotyping revealed that 2 HCWs were the most probable source of infection in 4 patients. Conclusions: Genotyping using PFGE is highly significant in studying the epidemiology of MRSA. HCWs should be seriousely considered, not only as a source of infection, but also as a major cause for transmitting infection between patients in different wards.