Objectives: This study investigated potential associations between having a person in need of nursing care at home and psychological distress amongst the Japanese working population, using a nationally representative sample. Methods: We extracted data from the 2013 Comprehensive Survey of Living Conditions conducted by the Ministry of Health, Labour and Welfare of Japan. The original survey was conducted amongst 295,367 households in 5,530 randomly selected municipalities. We analyzed participants aged 25-65 years who headed a household. The original questionnaire included questions about the specific qualifications required to receive long-term care insurance benefits, about psychological distress (measured using the K6 scale), and other covariates. If a family contained a member in need of nursing care at home, the person who headed that household was recognized as the participant who had a person in need of nursing care at home. Multiple logistic regression analysis was conducted to investigate the association between having a person in need of nursing care at home and psychological distress. Results: A total of 36,193 men and 2,765 women were included in the analysis, 2.9% of whom had a person in need of nursing care at home. Statistical analysis revealed an association between having a care-requiring older relative at home and psychological distress (odds ratio: 1.40, 95% confidence interval: 1.01-1.93). Conclusions: Having a person in need of nursing care at home appears to be positively correlated with worsening mental health of working populations in Japan.