A study was conducted to determine the interrater and test–retest reliability of the Motor Development Checklist (Doudlah, 1976). Thirty-six subjects with diagnosed multiple disabilities and severe and profound mental retardation were evaluated by two experienced occupational therapists. Reliability was established by means of the intraclass correlation approach, and results indicated that coefficients ranged from .93 to .99. The study results suggest that the Motor Development Checklist, when administered by experienced raters, can provide consistent information regarding the spontaneous motor performance of persons with multiple disabilities. Implications for practice and future research are briefly discussed.