<p>Hospitalization in an intensive care unit (ICU) or cardiac intensive care unit (CICU) can cause significant psychological distress in relatives, including anxiety, depression, and post-traumatic stress symptoms (PTSS). This study examined differences in these symptoms between ICU and CICU relatives, as well as factors contributing to symptom severity, independent of unit type. A cross-sectional design was used with 134 adult relatives (78 ICU, 56 CICU) from two Greek hospitals. Sociodemographic and clinical data were collected, and anxiety, depression, stress, and PTSS were assessed using the Depression Anxiety Stress Scales-21 (DASS-21) and the Greek version of the Impact of Event Scale–Revised (IES-R-Gr). Results indicated that ICU relatives reported significantly higher scores across all symptom scales compared to CICU relatives. Patient age, hospitalization duration, kinship, and relative’s perception of the patient’s life threat appeared to account for the effect of unit type, while female gender stands out as an independent risk factor across all symptom dimensions. These findings indicate that, although relatives of ICU patients experience greater psychological burden than those of CICU patients, likely due to the sudden and unpredictable nature of life-threatening events in the ICU, families in both settings show substantial distress and differing risk profiles by ICU type, gender, and kinship, underscoring the need for routine screening and tailored psychosocial support.</p>