Background: Leadership style has been given importance in contemporary research because leaders are considered to be an essential part of an organization's success. Toxic nurse managers can have a detrimental impact on the organization's bottom line by increasing nurse's absenteeism, creating job dissatisfaction and unnecessary job stress, resulting in high staff turnover and counterproductive work behaviors (CWB). Aim: The present study aimed to examine toxic leadership of nurse mangers and its relation to counterproductive work behaviors and intention to quit from the perspective of staff nurses. Design: A descriptive, correlational and comparative design was utilized to fulfill the aim of this study. Sample: A convenient sample (n=190) of staff nurses who agreed to participate in the study were included. Setting: The current study was conducted in two different selected sectors at Cairo governate. Tool: Three tools were used I. Toxic Leadership Behaviors of Nurse Managers (ToxBH-NM) Questionnaire; II. Counterproductive Work Behaviors Questionnaire (CWBs) and III. Nurses' intention to quit Questionnaire (NITQ). The results: The study revealed that, the majority (73.6%, 63.1 respectively) of staff nurses perceived a low level of overall nurse manger toxic leadership at both Hospitals. While only (14.9%, 15.5% respectively) of them perceived a high level of overall nurse manger toxic leadership at both Hospitals. Moreover, (100%) of staff nurses perceived a low level of overall Counterproductive Work Behavior at private Hospitals compared to (40.8%) of staff nurses perceived moderate level of overall Counterproductive Work Behavior at public Hospitals. Furthermore, (51.7%, 48.3% respectively) of staff nurses had low to moderate intention to quite level at private Hospitals compared to (33.0 %,514% respectively) of staff nurses had low to moderate intention to quite level at public Hospitals. While, only (15.6%) of staff nurses had low intention to quite level at public Hospitals. In addition, there was a statistically positive significantly correlation between total staff nurses perceived toxic leadership with their Counterproductive Work Behavior (r = 0.250& p= 0.02) at private hospital. While, there was a statistically positive significant correlation between total staff nurses' perceptions of toxic leadership with their intention to quit (r=0.352** and p= 0. 000*) at public hospital. Conclusion: Overall, the study concluded that, the majority of staff nurses perceived a low level of nurse manger toxic leadership at both private and public hospitals. All staff nurses perceived a low level of overall Counterproductive Work Behavior (CWB) at private hospital compared to around half of staff nurses perceived moderate level of CWB at public hospital. Around half of staff nurses had low to moderate level of intention to quite at both private and public hospitals. Also, there was a highly positive statistically significant correlation between staff nurses' perception of nurse managers' toxic leadership, with their Co...