Background <p>Safety behaviors (SBs), or unnecessary protective actions, are thought to play a key role in the development and maintenance of pathological fear and anxiety. However, their impact on exposure therapy outcomes is debated, with empirical studies yielding inconsistent findings. Thus, rather than continuing to test whether safety behaviors impact exposure therapy outcomes, we aimed to examine under which conditions safety behaviors may interfere with or facilitate exposure therapy outcomes.</p> Methods <p>Spider-fearful adults (<i>N</i> = 56) completed a 30-min exposure intervention using a standardized, experimenter-selected safety behavior (rubber boots). Participants were randomized to safety behavior condition, where the boots were faded out, unfaded, or not used during exposure.</p> Results <p>Both unfaded and faded safety behavior use groups approached the spider more closely during the intervention and found the intervention more acceptable. However, this had little impact on treatment outcomes, with all groups showing similar benefits at post-treatment and follow-up. Moderation analyses additionally showed that unfaded safety behavior use benefited highly distress intolerant participants, while fading safety behaviors undermined exposure when they blocked a participant’s threat expectancies.</p> Conclusions <p>Our findings highlight the importance of considering individual differences in the study of safety behavior use during exposure therapy and suggest that safety behavior use may be beneficial to certain subgroups, such as those who may be hesitant to begin exposure. This study was registered at <a href="http://www.clinicaltrials.gov">http://www.clinicaltrials.gov</a> (NCT04470882).</p>