This study examines the reliability and validity of a new assessment, the School Setting Interview (SSI), which is in process of being developed. The SSI is an interview assessment designed to determine the need for adjustments in the school setting for students with motor disabilities. The approach is descriptive and includes 11 content areas. Forty-five severely disabled students attending their first semester in one of the four Swedish upper secondary schools which have special resources for this group were enrolled in the study. Thirteen occupational therapists employed in the treatment departments assessed all the students using the SSI. Seventeen of the students were randomly chosen for a retest conducted by the first author. The reliability in terms of sensitivity, specificity and interrater reliability was examined. The content validity was also examined. The results show that the SSI is a highly sensitive assessment. According to the calculations, interrater reliability for the content areas is good or very good. The 11 content areas appear to be adequate for the intended purpose of the assessment, although some additional content areas, which could be added to the assessment, were identified.