The persistent head rocking of a woman diagnosed with profound mental retardation was examined during three separate assessments. First, a functional analysis demonstrated that head rocking was maintained independent of social consequences. Next, an antecedent assessment revealed that exposure to alternative sources of stimulation reduced head rocking, but only when the stimulation was being provided. A third assessment, which consisted of an enriched environment, replicated the ยฎndings of the ยฎrst two assessments. Across all three assessments, head rocking persisted at extremely high rates when alternative stimulation was unavailable and returned to high levels immediately following the removal of alternative sources of stimulation. An environmental enrichment (EE) intervention, which was based on the results of the functional analysis and antecedent assessment, resulted in a 70% reduction in the occurrence of the head rocking. In addition, a social validity assessment revealed that the participant's caregivers rated the EE intervention as both eective and socially acceptable. The particular challenges that satiation-resistant aberrant behavior presents for behavior analysts are addressed. Speciยฎc suggestions for research on intervention strategies for persistent aberrant behavior are also provided.