Objective To develop an inpatient experience evaluation scale for unaccompanied care services (also known as "non-family attendant care services") and to test its reliability and validity. Methods Following the COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) guidelines, the initial scale was developed through qualitative interviews, literature review, Delphi expert consultation, and cognitive interviews.A survey was then conducted among 230 patients to refine the items using item analysis and exploratory factor analysis (EFA).An additional sample of 393 patients was recruited to evaluate the scale′s psychometric properties. Results The final scale consisted of 14 items across three dimensions:service content, service competence, and service attitude.EFA yielded a cumulative variance explained of 82.548%.Confirmatory factor analysis showed a good fit for the first-order three-factor model.The item-level content validity index （I-CVI） ranged from 0.846 to 1.000, and the scale-level content validity index/universal agreement （S-CVI/UA） was 0.929.The overall Cronbach′s α coefficient was 0.924, and the test-retest reliability was 0.925. Conclusion The inpatient experience evaluation scale for unaccompanied care services demonstrates good reliability and validity, and can be used to assess inpatient experience with such care services.