The paper addresses the assessment of sensorimotor and communication skills in profoundly/multiply handicapped children. The problems inherent in assessing this population are described, including lack of validity of developmental norms established on children with intact sensory systems. Factors affecting sensory organization are reviewed, including attention, arousal and state, self-stimulation, complex visual system problems, and functional hearing. Typical problems involved in assessing the cognitive development of profoundly handicapped children are cited in a review of the Sensorimotor Cognitive Assessment "means-ends" subscale. Effects of sensory, motor, and cognitive factors on the child's grasping, approach or reach, and ability to make things happen are considered. Assessment of communication with this population begins with evaluation of signal levels. Modes of communication (visual, auditory, tactile components) and the effects on meaning are discussed. The relationship between communication and interpersonal attachment is commented upon in a final section. (CL)