We describe a clinical case study surrounding the behavioral assessment and operant treatment of, an adult with severe mental retardation who engaged in chronic breath-holding. In this clinical case, previous neurological and medical testing had ruled out biological bases for the individual's breath-holding. A functional behavioral assessment suggested that breath-holding was likely maintained by contingent staff attention. Treatment analysis consisted of the following conditions: baseline, physical redirection, fixed-time schedule of attention, differential reinforcement of other behavior, and a treatment package. Ultimately, a treatment package consisting of physical redirection and differential reinforcement of other behavior was found to be the most viable treatment option, reducing rates of breath-holding by 50%. (Contains 3 figures.)