Aims and objectivesTo explore and describe how parents of preterm and/or sick infants in neonatal care perceive their sleep. BackgroundParents experience many stressful situations when their newborn infant is preterm and/or sick. This affects bonding. By developing more family-centred care units with single-family rooms, parents are given the opportunity to stay and care for their newborn infant(s) 24hours a day. Lack of sleep may affect new parents' ability to cope with the many challenges they face on a daily basis. DesignA phenomenographic study with an inductive and exploratory design. MethodsSemi-structured interviews were conducted with twelve parents of infants in neonatal care between January-March 2012. To describe variations in perception of the phenomenon, data were analysed using phenomenography. FindingsFour descriptive categories were identified within the phenomenon sleep in parents of preterm and/or sick infants in neonatal care: impact of stress on sleep; how the environment affects sleep; keeping the family together improves sleep; and, how parents manage and prevent tiredness. ConclusionAnxiety, uncertainty and powerlessness have a negative influence on sleep. This can be decreased by continuous information, guidance and practical support. Skin-to-skin care was perceived as a stress-reducing factor that improved relaxation and sleep and should be encouraged by the nurse. The parents also mentioned the importance of being together. Having a private place where they could relax and take care of themselves and their newborn infant improved sleep. It was also desirable to involve older siblings in order to decrease feelings of loneliness, sadness and isolation. Relevance for clinical practiceImproved parental sleep in neonatal care may help the families cope with the situation and facilitate problem-solving, emotional regulation and the transition to parenthood.