Improvisational theater is defined broadly as a theatrical setting in which, process and product co-occur (Sowden, Clements,Redlich, & Lewis, 2015). Therefore, practicing improvisational theater involves embracing uncertainty (Napier, 2004). Inthis context, individuals may learn to tolerate uncertainty with greater comfort, a common treatment outcome across manypsychological disorders (e.g. Boswell et al., 2013). The current study employs a lab-based paradigm linking brief impro-visational theater experience to increased divergent thinking outcomes (Lewis & Lovatt, 2013). We set out to replicateand extend this finding by including an explicit measure of uncertainty tolerance. Across two studies, our results showincreased uncertainty tolerance for people who improvised, significantly more than people who participated in a socialinteraction control with limited uncertainty. Additionally, the improvising condition predicted relative improvement on asubset of divergent thinking measures, offering partial support for the Lewis and Lovatt (2013) finding that improvisationaltheater exercises can improve creativity.