Background: The admission of a family member to intensive care represents an emotionally complex experience, often characterised by anxiety, stress and uncertainty. ICU diaries, compiled by nurses and family members, have been proposed as a useful tool to support caregivers’ psychological well-being, improve communication and humanise the care environment. The aim of the study was to describe the content of ICU diaries filled out by family members to explore the experiences and meanings attributed to the diaries. Methods: The study used a qualitative approach based on thematic analysis of diaries completed by 16 family members of patients admitted to intensive care units. The data were coded and analysed to identify recurrent themes and to understand the emotional and psychological experience of the family members. Results: Three main themes emerged from the analysis: time, the family context (including maintaining contact with the patient, the relatives‘emotions, fear of suffering, spirituality, the person at the centre of the relatives’ lives and connection with the outside world) and the usefulness of the diary in understanding the care process. The diaries facilitated the continuity of the affective bond with the patient, offered a space to express emotions and improved communication with healthcare professionals. Conclusion: The results highlight the value of ICU diaries in supporting family members during the patient’s admission, reducing stress and strengthening the relationship with the healthcare team. The practical implications suggest the importance of promoting the structured use of diaries to foster more empathetic and family-centred care. Clinical trial number: Not applicable.