OBJECTIVES:  Modern therapeutics and healthcare improvements prolong stroke patient’s survival, however, the degree of disability remains high. It requires them having caregivers, especially in the first year after the onset. Longitudinal assessment of quality of life (QOL) and caregiver burden (CGB) and factors associated with these are limited among caregivers of stroke patients. The research aims to define the changes in QoL and CGB in first year of caregiving among the caregivers of stroke patients and to identify factors associated with it. METHODS:  Prospective, multi-centered observational study was conducted in the nine public hospitals in Mongolia. We used the WHOQOL-BREF questionnaire for assessing QoL and the Montgomery Caregiver Burden Scale for assessing CGB, and repeated after 1 year. Stroke patient characteristics were included for analysis. Generalized estimating equations were conducted to determine the factors associated with QoL. Multinomial logistic regression were conducted to analyze CGB change. RESULTS: QoL in the psychological health (p = 0.003) and social relationship (p < 0.001) domains improved after 1-year of caregiving; however, physical health declined (p = 0.47), but this decline was not significant. The factors associated with low QoL were poor physical health (β = −9.11, p = 0.013) and financial difficulties (β = −9.73, p = 0.008). None of the variables from stroke patients’ were significantly associated to caregivers’ QoL. Caregiver burden had increased in demand burden (p = 0.034), while objective (p = 0.568) and stress burden (p = 0.016) had decreased. Factors associated with these changes in CGB were caregiver’s marital status, relationship to the patient, financial difficulties, and patient’s gender and dependency. CONCLUSIONS:  This study provides information on factors predicting QoL and CGB change in first year of caregiving, which suggests social or financial support would be helpful for improving QoL and decreasing CGB among the caregivers who take care of post-stroke patients.