ABSTRACT: INTRODUCTION: Studies have reported associations between diaries kept for intensive care unit (ICU) patients and long-term quality-of-life and psychological outcomes in patients and their relatives. Little was known about perceptions of healthcare workers reading and writing in the diaries. We investigated healthcare worker perceptions to better understand their opinions and responses to reading and writing in the diaries. METHODS: We used a phenomenological approach to conduct a qualitative study of 36 semi-structured interviews in a medical-surgical ICU in a 460-bed tertiary hospital. RESULTS: Two domains of perception were assessed, reading and writing in the diaries. These two domains led to four main themes in the ICU workers' perceptions: suffering of the families; the diary as a source of information for families but also as generating difficulties in writing bad news; determining the optimal interpersonal distance with the patient and relatives; and the diary as a tool for constructing a narrative of the patient's ICU stay. CONCLUSIONS: The ICU workers felt the diary was beneficial in communicating the suffering of families while providing comfort and helping to build the patient's ICU narrative. They reported strong emotions related to the diaries and a perception of intruding into the patients' and families' privacy when reading the diaries. Fear of strong emotional investment may adversely affect the ability of ICU workers to perform their duties optimally. ICU workers are in favour of ICU diaries, but activation by the diaries of emotions among younger ICU workers may require specific support.