Introduction: Informal caregiving during hospitalization of older adults is significantly related to hospital processes and patient outcomes. Studies in home settings demonstrate that ethno-cultural background is related to various aspects of informal caregiving; however, this association in the hospital setting is insufficiently researched. Objectives: Our study explore potential differences between ethno-cultural groups in the amount and kind of informal support they provide for older adults during hospitalization. Methods This research is a secondary data analysis of two cohort studies conducted in Israeli hospitals. Hospitalized older adults are divided into three groups: Israeli-born and veteran immigrant Jews, Arabs, and Jewish immigrants from the Former Soviet Union (FSU). Duration of caregiver visit, presence in hospital during night hours, type of support (using the Informal Caregiving for Hospitalized Older Adults scale) are assessed during hospitalization. Results are controlled by background parameters including functional Modified Barthel Index (MBI) and cognitive Short Portable Mental Status Questionnaire (SPMSQ) status, chronic morbidity (Charlson), and demographic characteristics. Results: Informal caregivers of "FSU immigrants" stay fewer hours during the day in both cohorts, and provide less supervision of medical care in Study 2, than caregivers in the two other groups. Findings from Study 1 also suggest that informal caregivers of "Arab" older adults are more likely to stay during the night than caregivers in the two other groups. Conclusions: Ethno-cultural groups differ in their patterns of caregiving of older adults during hospitalization. Health care professionals should be aware of these patterns and the cultural norms that are related to caregiving practices for better cooperation between informal and formal caregivers of older adults.