ABSTRACT There appears to be justification for the use of sensory techniques with individuals dually diagnosed with mental illness and mental retardation. Sensory integration, sensorimotor therapy, and sensory stimulation approaches have been reported to yield functional gains when used with persons who have mental retardation, schizophrenia, and autism. The theory of sensory integration has enabled occupational therapists to understand the nature of sensory-driven behaviors resulting from the breakdown of central nervous system processing that is a common feature in individuals dually diagnosed with mental retardation/mental illness and autism. Self-stimulatory and self-injurious behaviors demonstrated by these individuals are often a reflection of an underlying neurological dysfunction. Treatment procedures using sensory stimuli which have an organizing and integrating effect on central nervous system processing can be employed to reduce dysfunction and enhance function.