Although dual-task interference is ubiquitous in a variety of task domains, stop-signal studies suggest that response inhibition is not subject to such interference. Nevertheless, no study has directly examined stop-signal performance in a dual-task setting. In two experiments, stop-signal performance was examined in a psychological refractory period task, in which subjects inhibited one response while still executing the other. The results showed little evidence for the refractory effect in stop-signal reaction time, and stop-signal reaction time was similar in dual-task and single-task conditions, despite the fact that overt reaction times were significantly affected by dual-task interference. Therefore, the present study supports the claim that response inhibition does not suffer dual-task interference. (Contains 9 tables, 6 figures and 2 footnotes.)