This cross-sectional study explored the work-related and individual factors that contributed to the occurrence of low back pain and affected activities of 36 personal care workers at an old age home in Hong Kong. The study was divided into four parts: (1) a questionnaire documenting workload exposure factors; (2) a musculoskeletal symptoms survey documenting the prevalence of low back pain in this group of workers; (3) a worksite evaluation focusing on personal care workers' work postures and the work environment; and (4) an evaluation of physical fitness and lifting capacities of personal care workers. Univariate followed by multiple logistic regression analyses were used to identify the risk factors associated with low back pain that affected work activities. The results revealed that low back pain was associated with the perceived physical demands of cleaning tasks (odds ratio [OR] = 7.28, 95% confidence interval [CI] = 1.35-39.35, P < .05), perceived demands of awkward sustained back (OR =4.46, CI =0.86-22.97, P =.074) and neck (OR =0.18, CI =0.04-0.81, P < .05) postures, and thermal stress at work (OR =49.80, CI =0.70-3541.79, P =.072). The results of the current study indicated that the work environment contributed to low back pain at work. Workers perceived that exertion in workplaces has a role in assessing workplace risk. To avoid progression of low back pain in the workplace, work adjustment or modification should be considered when workers report high levels of perceived exertion at work.