Background/Aims: Caregivers perform an important role but caring affects other roles they perform, resulting in poor time management and reduced quality of life. This study aimed to compare the time-use patterns and self-efficacy of caregivers of two groups of patients with chronic disease: those with a diagnosis of mental illness and those without a diagnosis of mental illness. Methods: Family caregivers of patients with a chronic disease who were aged between 20–60 years, resident in Arak, not taking care of another patient and literate were eligible to participate. The presence of mental illness was based on a psychiatrist's diagnosis at least 6 months before the study. The Mothers' Time Use Questionnaire, Sherer Self-efficacy Scale and a demographic questionnaire were used to capture data relating to time-use, self-efficacy and participant characteristics. Data were analysed using independent t-test and Mann–Whitney U test to identify and compare time-use patterns and self-efficacy. Results: There were no significant between-group differences in demographics or mean time-use scores in six domains (rest/sleep, leisure, housework, work/occupation, social participation and satisfaction with time management). Self-care time-use scores (time, quality, importance and enjoyment) were significantly higher for caregivers of patients with chronic disease with a diagnosis of mental illness. Patient care time-use scores were significantly higher for caregivers of patients with chronic disease without a diagnosis of mental illness. Mean self-efficacy score was significantly higher in the group caring for patients with a diagnosis of psychiatric disease. Conclusions: Chronic physical illnesses may result in greater dependence on caregivers than mental illness, increasing the amount of time spent on care and reducing caregiver self-efficacy.