A cross-sectional questionnaire study was conducted on cooks working for nursery schools in N city in order to verify epidemiological evidence of the work-relatedness of low back pain among them. After female workers aged 30 or more were selected from a study base of 2,799 workers in social welfare facilities, low back pain prevalence of cooks (n = 240) was compared with nursery school teachers (n = 955). Age-standardized prevalence ratios (PRs) of low back pain were 1.9 (95% CI: 1.5-2.5) in cooks compared with nursery school teachers. Among cooks, relative risks of low back pain increased with the increase in the number of lunches to be prepared and decreased with the increase in the number of cooks making lunches in a logistic regression model controlling age and body length. Low back pain was also found to be associated with self-estimated job stressors/ work load by logistic regression models. Multifactorial effects from ergonomic and psychosocial factors, and individual factors on the low back were suggested. From the viewpoint of epidemiological criteria for work-relatedness, it was concluded that the work-relatedness of low back pain among cooks in nursery schools was partially supported.