Ergonomics' is composed of two words which are 'ergo' a Greek word meaning work, and 'nomics' which means study. Ergonomics factors that contribute to the health are inappropriate lighting, tools design, chair design, heavy lifting and repetitive motion and others. These factors can cause musculoskeletal disorders (MSDs). The aim of this study was to assess ergonomic effect on workers of ultrasound and microbiology areas in King Abdulaziz Medical City, (KAMC)-Riyadh. The second objective of this study was to identify the ergonomic factors and the presence of work related injuries, also to compare awareness of ergonomics of work sites of health workers. This study was a cross sectional quantitative study conducted at KAMC,National Guard Hospital (NGH), the sample size for workers in radiology department was 27, and the sample size for workers in the laboratory was 27. Two questionnaires distributed among laboratory and radiology workers constructed of questions and demographic data were adapted for our study to determine the effect of ergonomics, the most common physical problems that workers experience in their workstation, and the awareness of ergonomic among the health care workers 18 participants (40.0% of the total) from the Microbiology-technicians were completed the questionnaire and were 27 participants (60.0%) form the Ultrasound-sonographers completed the questionnaire. There was an ergonomic effect on gender for microbiology technicians (p-value was 0.043). Moreover, the ultrasound-sonographers had a significant association between gender and pain related to work (p value < 0.001). Awareness however, in microbiology technicians, vas found to be 83% who knew the meaning of ergonomics and 85% in ultrasound sonographers. In conclusion, there was a significant effect of ergonomic on sonographers and microbiology technician. The study showed a good level of knowledge and awareness about ergonomics, however, still there is a quiet high percentage of them who did not receive health education on ergonomics and also a high percentage who aren't implementing ergonomics. There is a need for educational and implementation empowerment programs in this regard.