A 21-item test entitled Assessment of Sensorimotor Integration in Pre-School Children (1) was developed to measure vestibular-based functions in pre-school children. It focuses on postural control, reflex integration, and bilateral motor integration. Data were gathered on 113 normal and 23 developmentally delayed children from three to five years of age. The psychometric quality of the test was investigated in terms of domain validity, discriminant validity, and interobserver reliability. It was found that 1. the items validly measure the domain of vestibular-based functions, 2. the six component subtests provide strong discriminative power and a high degree of accuracy for classifying children as normal and delayed, and 3. the test could be administered with a high degree of objectivity by therapists with little or no experience in sensory integrative testing. These findings should be regarded as tentative until cross-validation studies and research on construct validity and decision-making reliability have been conducted.