In this study, we addressed the effect of stereoscopy on presence, anxiety, and cybersickness in a virtual public speaking world, and investigated the relationships between these three variables. Our results question the practical relevance of applying stereoscopy in head-mounted displays (HMDs) for virtual reality exposure therapy (VRET) in a virtual public speaking world. In VRET, feelings of presence improve the efficacy (B. K. Wiederhold & M. D. Wiederhold, 2005). There are reports of a relatively large group of dropouts during VRET at low levels of presence in the virtual environment (Krijn, Emmelkamp, Olafsson, & Biemond, 2004). Therefore, generating an adequate level of presence is essential for the success of VRET. In this study, 86 participants were recruited and they were immersed in the virtual public speaking world twice: once with stereoscopic rendering and once without stereoscopic rendering. The results showed that spatial presence was significantly improved by adding stereoscopy, but no difference for reported involvement or realism was found. The heart rate measurements also showed no difference between stereoscopic and nonstereoscopic viewing. Participants reported similar anxiety feelings about their talk and similar level of cybersickness in both viewing modes. Even though spatial presence was significantly improved, the size of statistical effect was relatively small. Our results therefore suggest that stereoscopic rendering may not be of practical importance for VRET in public speaking settings. © 2012 by the Massachusetts Institute of Technology.