Musculoskeletal disorders (MSDs) are considered a growing problem among healthcare personnel, especially service workers. The emergency room (ER) service workers are highly exposed to work-related risk factors which predispose them to MSDs. A cross-sectional study was performed on 78 ER workers. Full medical and occupational histories were taken. The Standardized Nordic Questionnaire (SNQ) was used for the assessment of musculoskeletal symptoms. Clinical examination was done with special emphasis on the locomotors system, and serum levels of muscle enzymes, including creatine kinase (CK) and creatine kinase isoenzyme (CK-MM) were measured. The study aims to detect the prevalence of occupational musculoskeletal disorders (MSDs) among ER workers at University hospitals, and assessment of CK-MM as a biomarker used in the early detection of MSDs. We found that 71.8% of the participants were complaining of musculoskeletal disorder in the last days before the study, while only 34.6% were complaining of musculoskeletal disorder in the last 12 months before the study. The knee joint was the most commonly affected site in the past 7 days, by 39.7%. On the other hand, the highest prevalent disorder in the last 12 months was for the ankle joint (17.9%) with significantly high levels of serum CK-MM. In conclusion, musculoskeletal injuries are a common complaint among healthcare occupations, especially among ER service workers that need regular health education and ergonomic training programs. Monitoring of serum CK-MM level with cut-off value 90 ng\ml could be used as a novel approach for the early detection of work-related musculoskeletal disorders.