Aim: Of the few instruments available to measure the important, positive aspects of caring, the Caregiver Reaction Assessment is regarded as the most suitable, but there is no validated Spanish version. The aim of this study was to translate the Caregiver Reaction Assessment into Spanish and assess its psychometric properties. Methods: The Caregiver Reaction Assessment was translated into Spanish and then back translated. Validation included construct validity, criterion validity and reliability: 287 interviews were conducted with informal caregivers of patients with dementia between November 2010 and April 2012. Results: Principal component analysis confirmed the original instrument's five subscales. Criterion validity showed a moderate negative correlation between the impact on health and the EQ‐5D (r = −.43), that is, a greater impact on health correlated with lower health‐related quality of life. The Caregiver Reaction Assessment showed good internal consistency, with a Cronbach alpha of .804, and good temporal stability for the distinct subscales, with intraclass correlation coefficients varying from .683 to .729 (p < .001). Conclusion: The Caregiver Reaction Assessment is a reliable, valid instrument for the measurement of the reactions of informal caregivers of patients with dementia, with good psychometric properties.