OBJECTIVES: The aim of this study is to examine the prevalence, to report barriers and mental health impact of bullying behaviours and to analyse whether psychological support at work could affect victims of bullying in the healthcare workplace.DESIGN: Self-administered questionnaire survey.SETTING: 20 in total neonatal intensive care units in 17 hospitals in Greece.PARTICIPANTS: 398 healthcare professionals (doctors, nurses).MAIN OUTCOME MEASURES: The questionnaire included information on demographic data, Negative Act Questionnaire-Revised (NAQ-R) behaviour scale, data on sources of bullying, perpetrators profile, causal factors, actions taken and reasons for not reporting bullying, psychological support and 12-item General Health Questionnaire (GHQ-12) scores to investigate psychological distress.RESULTS: Prevalence of bullying measured by the NAQ-R was 53.1% for doctors and 53.6% for nurses. Victims of bullying differed from non-bullied in terms of gender and job experience, among demographic data. Crude NAQ-R score was found higher for female, young and inexperienced employees. Of those respondents who experienced bullying 44.9% self-labelled themselves as victims. Witnessing bullying of others was found 83.2%. Perpetrators were mainly females 45-64 years old, most likely being a supervisor/senior colleague. Common reasons for not reporting bullying was self-dealing and fear of consequences. Bullying was attributed to personality trait and management. Those who were bullied, self-labelled as a victim and witnessed bullying of others had higher GHQ-12 score. Moreover, psychological support at work had a favour effect on victims of bullying.CONCLUSIONS: Prevalence of bullying and witnessing were found extremely high, while half of victims did not consider themselves as sufferers. The mental health impact on victims and witnesses was severe and support at work was necessary to ensure good mental health status among employees.