The aims of the present study were to investigate the prevalence of LBP among institutional caregivers of people with intellectual, autistic or associated multiple disabilities and to examine the risk factors for LBP among this population. A crosssectional, purposive sampling method was used to recruit into the study 1073 staff who were working in 15 disability welfare institutions. The survey materials included an introduction letter, an informed consent, and a structured questionnaire that queried the participant's demographic and working characteristics, healthy lifestyle, and previous and current LBP experiences. The present study results showed that 63.2% of the participants reported that they had LBP in the previous year. Many factors of the participants' demographic characteristics (gender, BMI, and marital status), working conditions (years of working experience, weekly work days, labor-oriented work, and direct care staff), and health status (exercise habit, perceived health status, previous and more recent medication experience of musculoskeletal discomfort) associated with LBP occurrence were analyzed in univariate Chi-square analyses. Finally, multiple logistic regression analyses revealed that the factors of female gender (OR = 1.534, p = 0.039), being married (OR = 1.469, p = 0.027), being direct care staff (OR = 1.844, p = 0.025), having fair health status (OR = 1.518, p = 0.012), or previous (OR = 1.996, p < 0.001) and more recent (OR = 2.744, p < 0.001) medication experience of musculoskeletal discomfort were found to be more likely to have LBP than their counterparts. This study highlights that we should pay much closer attention to LBP risk factors and to plan necessary initiatives to avoid the progression of LBP in the workplace.