Background father's sense of security in the early postnatal period is important for the whole family. An instrument, which measures Parents' Postnatal Sense of Security (the PPSS instrument), is under development.

Objective to explore and describe factors, which influence fathers' sense of security during the first postnatal week.

Methods an explorative design with a qualitative approach was used. Thirteen fathers from three hospital uptake areas in Southern Sweden were interviewed using focus group discussions and individual interviews. Analysis was carried out using qualitative content analysis.

Findings participation in the processes of pregnancy birth and early parenthood emerged as the main category for fathers' postnatal sense of security. The emergent categories were; ‘willingness to participate and take responsibility’, ‘being given the opportunity to take responsibility’, ‘being assured about mother's and baby's well-being’, ‘having someone to turn to—knowing who to ask’, ‘being met as an individual’ and ‘being met by competent and supporting staff’.

Key conclusions and implications for practice new and specific items of importance when investigating fathers' sense of security during the early postnatal period have been pinpointed. Fathers' sense of early postnatal security may be enhanced by giving them a genuine opportunity to participate in the whole process and by giving them the opportunity to stay overnight at the hospital after the birth. Midwives and care organisations need to give clear information about where competent help and advice can be obtained at all hours. Midwives should strengthen the fathering role by acknowledging and listening to the father as an individual person.