This study provides insight into the experience of ‘being’ an ICU nurse and relative of a critically ill patient. Current research focuses mainly on the needs of family members of critically ill patients, with several qualitative studies describing the experience. The specific experience of ICU nurses as relatives is absent in current research. This is a New Zealand based phenomenological study informed by the work of Gadamer and van Manen. Data from interviews of four ICU nurses who had experienced having a family member admitted to ICU was analysed using van Manen’s framework. The experience of being an ICU nurse when a family member is admitted to ICU is described in the following themes: A nurse’s nightmare; knowing and not knowing; feeling torn; and gaining deeper insight and new meaning. van Manen’s lifeworld existentials assist in gaining a deeper understanding of the findings. New and deeper understanding provides a rationale for ICU nurses from which to improve nursing practice. Recommendations for organisational support for ICU nurse/relatives, education for staff and further research are made based on the findings of this study.