Objectives: Considering the effect of sex and head of household responsibilities, this study was designed to evaluate whether precarious employment is associated with the development of new-onset severe depressive symptoms. Methods: We followed 2214 male and 1276 female waged workers, ≤59 years of age and without moderate depressive symptom, from the Korean Welfare Panel Study 2007-2013. Their employment status was classified as full-time permanent, precarious, self-employed, or unemployed after baseline. Except for occupation and company size, all variables were treated as time-dependent. Severe depressive symptoms were measured using the 11-item Center for Epidemiologic Studies Depression Scale (CES-D-11). A generalized estimating equation was used to evaluate the effect of employment status on the development of new-onset severe depressive symptoms. Results: After adjusting for initial baseline CES-D-11 score, chronic disease, and other socioeconomic covariates, precarious employment was associated with the development of new-onset severe depressive symptoms among male heads of household [odds ratio (OR) 1.52, 95% confidence interval (95% CI) 1.02-2.25] and female heads of household (OR 4.19, 95% CI 1.70-10.32). In addition, the transition from full-time permanent employment to another employment status was associated with the development of new-onset severe depressive symptoms among both sexes, with an especially strong association among females. Conclusion: The present study suggests that, depending on head of household status and sex, precarious employment is associated with the development of new-onset severe depressive symptoms.