Background: Nursing has a reputation for being one of the most stressful occupations. As a result of their work, many nurses suffer from anxiety and depression. Nurses are also at risk of poor sleep owing to their work nature.This study aimed to examine the relationship between work–family conflict, sleep quality, and depressive symptoms among mental health nurses. A descriptive cross-sectional study design was utilized in this study. Setting/sample: This study was conducted at El Azazi Hospital for Mental Health, Al-Sharkia Governorate on 139 mental health nurses. Four tools were used in this study: Socio-demographic data sheet, Work–Family Conflict Scale, Arabic Pittsburgh Sleep Quality Index, and Arabic Center for Epidemiologic Studies Depression Scale. Results: Results revealed that, a significant percentage of mental health nurses suffered from poor sleep quality and depressive symptoms; there were highly statistically significantly positive correlations between work–family conflict (WFC) and both of Pittsburgh Sleep Quality Index (PSQI) and depressive symptoms among nurses. Conclusions: Working with psychiatric patients affected their nurses, which disturbed their sleep quality and led to depressive symptoms. As well, increasing work–family conflict in mental health nurses leads to poor sleep quality and depressive symptoms. Family interference with work, sleep quality, and work interference with family were statistically significant predictors of depressive symptoms. Recommendation: Training in the workplace, such as cognitive behavioral therapy and complementary and integrative health techniques, is recommended; involving nurses in work scheduling decisions, lowering nurses’ burden by increasing staffing, and honestly listening to nurses’ hopes and perspectives when difficulties occur from their job or family life are all ways to improve the work environment and reduce work–family conflict