To evaluate the mental health literacy regarding depression of Portuguese nurses working in a hospital setting. Methods: A descriptive cross-sectional study was conducted with nurses in Portugal. Mental health literacy was evaluated using QuALiSMental for depression. Summary statistics (e.g., percentage distributions) were calculated using SPSS 28. A point estimate and confidence interval for the proportion were used for inference. STROBE guidelines were used to report the study. Results: A total of 483 nurses completed the Questionnaire for Assessment of Mental Health Literacy (QuALiSMental). The results show good MHL, with a particular emphasis on recognizing depression (95% CI: 78.77-85.62). However, these values are not extendable to all components of MHL, with notable gaps in knowledge regarding some mental health first-aid strategies. Conclusion: The results observed in this study, although still distant from what is considered optimal, show-that nurses' MHL levels are generally positive. Adequate levels of MHL can contribute to using this knowledge to benefit one's mental health and that of others with whom they interact in their personal and professional daily lives. In the case of depression, adequate levels of MHL can help reduce the time between the onset of the first signs and symptoms and the provision of specialized help, potentially preventing the worsening of suffering and the progression to chronic situations.