This study define prevalence of upper musculoskeletal disorders (UMSDs) and identified physical risk factors associated with upper extremity disorders amongst aluminum factory workers in Saudi Arabia, during the spring of 2015. We administered a survey to 115 production line workers in an aluminum factory. Surveys addressed demographics, work history, job performance, pain and medical history. Three occupational health experts evaluated risk of UMSDs in each department and created an expert scale indicating UMSDs risk. Overall 45.2% of the workers reported at least one type of pain; joint pain was the most common. 39% of non-Saudi reported pain compared to 18% of Saudi. Muscle pain was associated (p ≤ 0.001) with repetitive movement (RR=5.8), lifting (RR=5.75), pushing and pulling (RR=5.17), awkward movement (RR=3.81). Joint pain was associated (p ≤ 0.001) with repetitive motion (RR=7.12), lifting (RR=3.28), pushing and pulling (RR=3.28) and awkward movement (RR=2.64). A logistic regression model including nationality (OR=3.229, CI=1.052, 9.9) (p=0.041), and department indicates that only anodizing (OR=5.286; CI=1.28, 21.77) (p=0.021), was related to muscle pain when using painting unit as a reference.