Although response blocking is widely used in the clinical treatment of problem behavior, research on the isolated effects of blocking is limited. Prior research has demonstrated the reductive effects of blocking by way of punishment or extinction. Contingent response blocking also has the potential to have a reinforcing effect or no effect on the blocked response. The purpose of the current study was to pilot a brief assessment designed to evaluate behavioral sensitivity to response blocking in the context of clinical practice. To address the challenges associated with assessing the effects of blocking on well-established problem behaviors, arbitrary responses were used. Results suggest that response blocking may have more disparate effects on responding than have previously been reported. Within-session analyses indicated that response blocking produced increases, decreases, and inconsistent effects on responding across participants. Clinical implications of these findings and avenues for future research on response blocking are outlined.