Background: Psychosocial adjustment to a complex and disabling long‐term condition like Parkinson´s disease is a complex, dynamic, cyclical and interactive process. Family caregivers, face multiple challenges that require a significant effort in terms of psychosocial adjustment, which must be considered by healthcare professionals in order to provide a holistic care. The patients’ self‐report version of the Psychosocial Adjustment to Illness Scale (PAIS‐SR), which has been validated in Spain for use in Parkinson's disease, is designed to evaluate the psychosocial adjustment of patients. Objectives: Our purpose was to validate the Spanish PAIS‐SR version for caregivers of patients with Parkinson's disease. Methods: An open, national cross‐sectional study with one point‐in‐time evaluation and retest was carried out in 450 family caregivers of patients with Parkinson's disease. Data were collected in Spain from April 2016 to September 2017. Results: The psychometric analysis performed showed that the Spanish version of the PAIS‐SR for caregivers presents adequate indicators of reliability, internal and external validity, and is structured according to the seven‐domain model proposed by the author of the instrument.