An observational research study based on sensory integration theory was conducted to examine the observed impact of student selected multi-sensory experiences within a multi-sensory intervention center relative to the sustained focus levels of students with special needs. A stratified random sample of 50 students with severe developmental disabilities ages eight to eighteen was selected for observation within a public school environment representing four classifications of students: TMH (Trainable Mentally Handicapped), PMH (Profoundly Mentally Handicapped), students with Autism, and students with Multiple Disabilities. An observation form representing 24 observable behaviors (facial expressions, vocal cues, and body language) defined in the literature was developed and pilot tested for construct validation and reliability purposes. Four trained observers completed inter-rater reliability analysis prior to the study. Observers completed observation forms for individual students for three 20-minute time periods (within the regular classroom, within the multi-sensory center, and after returning to the regular classroom). Sustained focus was measured by combining specific observed types of data reflecting student engagement and on-task behaviors as defined in the literature. Data were analyzed using repeated measures ANOVA. Findings of the study lend strong support for implementing multi-sensory experiences to increase the sustained focus of students with special needs. (Contains 9 figures.)