Background: The ASCOT-ER is an adapted easy-read version of the ASCOT-SCT4, a self-report measure of social care-related quality of life (SCRQoL) for social care evaluation. In this study, we investigated the instrument's feasibility, construct validity and factor structure. Method: Data were collected from 264 service users in England. Feasibility was evaluated by missing data and help to complete the questionnaire. Scale dimensionality was assessed using exploratory factor analysis. Construct validity was evaluated by hypothesis testing. Results: Convergent validity was supported by moderate to strong correlations between ASCOT-ER and personal wellbeing and overall quality of life, as well as with individual characteristics. Exploratory factor analysis indicated that the ASCOT-ER is a unidimensional scale. Low missingness indicates that the instrument is feasible; however, most respondents needed some level of support to complete the questionnaire. Conclusion: The study provides preliminary evidence of the ASCOT-ER's feasibility, unidimensionality and construct validity.