The current study aimed to measure the stress levels of family caregivers of individuals with mental illness and compare their stress levels according to the diagnosis and other sociodemographic characteristics. The sample comprised 310 family caregivers of individuals with mental illness in Jordan. Family caregivers completed a demographic checklist and the Arabic version of the Perceived Stress Scale 10-Item (PSS-10) questionnaire. A significant difference was found in PSS-10 levels among family caregivers according to gender, diagnosis of their family member, and time since diagnosis.