Background The increasing prevalence of moral distress in the stressful environment of the intensive care unit (ICU) provides grounds for nursing error and endangers patients’ health, safety, and even life. One of the most important reasons for this distress is the treatment team’s second victim syndrome (SVS), especially nurses, following errors in the treatment system. Objectives The present study aimed to determine the relationship between moral distress and SVS in ICUs. Research design This cross-sectional study involved a sample size of (...) 96 ICU nurses working in hospitals affiliated with Tehran University of Medical Sciences, Iran, in the 2021–2022 period, who were selected via a simple random sampling method. Data were collected using the Demographic Questionnaire, the second victim experience and support tool (SVEST) and Moral Distress Scale-Revised (MDS-R). Descriptive statistics (percentage, frequency, mean, and SD) and analytical tests (Spearman correlation coefficient test, independent t-test, and ANOVA) were employed for data analysis. Participants and research context This study used a sample size of 96 intensive care unit nurses working in hospitals affiliated to Tehran University of Medical Sciences selected by simple random sampling. Ethical considerations The study obtained research ethics approval, and all participants were informed of the voluntary and anonymous nature of their participation. Findings The results showed that 59.4% of nurses suffered a low level of moral distress, and 40.6% suffered from a moderate level of moral distress. The SVS score of 86.5% of the nurses was moderate. There was no significant and direct correlation between moral distress and SVS in nurses; however, there was a significant and inverse correlation between the moral distress intensity and SVS ( p = 0.011). Conclusion Despite no significant correlation between moral distress and SVS, these variables were at moderate levels. Accordingly, it is suggested to provide a proper ground for expressing morally stressful situations, counseling and training strategies to deal with moral distress, creating support resources for those suffering from SVS, and implementing empowerment programs. (shrink)