Background. It is normal for parents to experience a range of emotions and changes in behaviour while their newborn infant is in the NICU. The stress experienced by these parents during their infant’s hospital stay is found to affect the parent-infant relationship and their ability to bond reciprocally. Several studies have pointed out that support from family and friends can be useful for parents’ mental distress in this situation. Some differences are found between mothers’ and fathers’ experiences of the support. The aim of the current study is to examine parents’ perceived mental distress when their infant is admitted to a neonatal intensive care unit (NICU) and factors important for their support. The relationship between parents perceived mental distress and satisfaction with NICU care are spare researched. Methods. A multicentre prospective cohort study. A total of 568 parental participants from six different NICUs geographically spread throughout Norway. Hospital Anxiety and Depression Scale (HADS) and Impact of Events Scale-Revised (IES-6) were used to collect data. All the responses were rated and analysed using parametric analysis methods, descriptive statistics, logistic regression, factor analyses and linear regression analyses.Results. A total of 275 mothers reported receiving support from family and friends compared with 232 fathers. Younger parents had a higher OR of reporting anxiety compared with that of older parents. Parents with a primary or high school education level showed a higher OR of satisfaction than did parents with a college or university education level.Conclusion. There are differences in mothers’ and fathers’ responses to their experiences of various distress symptoms related to their children being in the NICU, as well as their received support from family and friends. There are also outcome differences between the age and education level of the parents and their experience of stress in the NICU. Mothers are more distressed and have more anxiety and depression than do fathers have.Trail registration: This project was first presented to the Regional Committees for Medical and Health Research Ethics which reported that the project was outside its mandate (2015/386). The project is approved from the Norwegian Data Protection Officials.