Background: Methicillin-resistant Staphylococcus aureus is increasing rapidly worldwide and is a public health concern. Methicillin-resistant Staphylococcus aureus (MRSA)is an important organism that causes both hospital-acquired and community-acquired infections. Its prevalence varies geographically and in different hospital settings. MRSA is resistant to all penicillin, beta-lactams and the cephalosporin group of antibiotics. There is increased risk of infection, mortality and morbidity associated with methicillin-resistant Staphylococcus aureus. Purpose: The purpose of this retrospective quantitative study is to document the prevalence and antimicrobial susceptibility patterns of MRSA using variables such as age, gender, specimen type, ward type, clinical infections and antibacterials used. Design: This project is a retrospective quantitative study utilising a positivist philosophical worldview with an objectivist epistemology. The data were collected from registry books and from the database of the different specimens sent in to the clinical microbiology laboratory for microscopy, culture and sensitivity testing that were analysed prospectively from 2012 to 2016.All confirmed MRSA cases were recorded with their susceptibility patterns. Data were collected at the hospital microbiology laboratory in Port Moresby General Hospital, Papua New Guinea, for a period of three months. The statistical treatment of data was aided by SPSS (version 25) employing descriptive and chi-square techniques. Results: A total of 1,006 MRSA isolates were confirmed in the five years from 2012 to 2016. The overall prevalence of MRSA was 63.9%. 529 patients were males and 474 were females. The predominant age groups were 0-5 years with 39% of the total MRSA and 20-39 years old with 13%. Many samples were swabs from wounds and skin and soft tissue infections, followed by venous blood. Surgical wards had the highest frequency of MRSA (26.7%). The sensitivity patterns of MRSA were as follows: vancomycin, 96%; tetracycline, 93%; chloramphenicol, 79%; erythromycin, 68%; and septrin, 64%. Statistical significance of p ≤0.05 was observed for the following categorical variables and antibacterials: gender with chloramphenicol (p=0.019);clinical infections with erythromycin (p=0.001); and clinical infections with septrin (p=0.001). Conclusion: The high prevalence of MRSA as found prompted a need for effective control measures and continued surveillance at the Port Moresby General Hospital, Papua New Guinea. With the significance of the sensitivity patterns, a continued antimicrobial surveillance and strict policies for empirical treatment should be created as well. Overall effective infection control policies and antimicrobial stewardship programmes need to be implemented, evaluated regularly and maintained.