This study examined procedures for the assessment and treatment of automatically reinforced vocal stereotypy of a 6-year-old girl with autism. Stimulus assessments were conducted to identify toys that were correlated with higher rates of vocal stereotypy and toys that were not. A concurrent operants assessment identified preferred stimuli (toys that produced auditory stimulation), which were then used as reinforcers for the non-occurrence of vocal stereotypy. A reversal design was used to compare the effects of a fixed time schedule of reinforcement (FT 1-min) to differential reinforcement for the non-occurrence of behavior (DRO) to reduce vocal stereotypy. Implementation of the FT schedule revealed no effect, whereas the DRO schedule led to a reduction in the target behavior during treatment sessions and across the school day. This study adds to the body of literature supporting the identification of matched stimuli to reduce non-socially mediated problem behavior.