Some epidemiological studies with a large number of subjects, like a national health study, reported that precarious employment was associated with increased depressive symptoms, but this hypothesis may not be applicable to precarious workers of all industry types. We examined the association between precarious employment and depressive symptoms in light of work-related stress in care work environments. The selfadministered questionnaire, composed of the Job Content Questionnaire based on the demand-controlsupport model and the Center of Epidemiological Studies Depression Scale (CES-D), was distributed, and a total of 1,338 permanent and 531 precarious employees responded to it with complete forms. In the precarious employees, scores of CES-D, job demand and job control were lower and supervisor support score was higher compared with the permanent employees, though there was no significant difference in the proportion of CES-D score ≥16 between the two groups. Multivariate analysis with adjustment for possible confounders revealed that increased depressive symptoms were associated with low coworker support in the precarious employees and with high demand and low control at work, low support from supervisors and coworkers in the permanent employees. However, precarious employment was not significantly associated with depressive symptoms in the male or female employees. In conclusion, our results do not support the above hypothesis at least in care service workers. Such a hypothesis should be verified in employees of each industry separately. Instead, coworker support within each workplace appears to be important for the preventive strategy of depression in workers including precarious employees.