Abstract: Visual and auditory information has dominated the field of virtual reality (VR). Evaluation of the role of sensory stimulation in VR has highlighted olfactory stimulation as a potentially powerful yet underutilized therapeutic tool. Early studies of immersive environments, which were run as experiments, incorporated smell in the virtual experience; however, olfaction in virtual environment design and development has arguably failed to maintain a position commensurate with its sensory capacity, exemplified by the paucity of research and possible application. A review of the literature suggests that olfaction as a component of virtual environment exposure therapy may be a useful addition in the treatment of posttraumatic stress disorder (PTSD) a mental health condition triggered by a terrifying event, either experiencing or witnessing it. Symptoms may include flashbacks, nightmares and anxiety, as well as uncontrollable thoughts about the event. However, to investigate the role of olfaction further research is required in the formulation, display, staging and customization of scent, coupled with an indepth analysis of the role of olfaction in cognitive function, memory, emotion and creation of presence, particularly in the context of VR treatment of PTSD. Benefits of olfactory therapy may, however, be compromised by the fact that olfactory identification deficit has been noted as a component of PTSD. Investigation is required into causative or reactive mechanisms that may underlie olfactory deficits and into suitable VR therapeutic protocols that could be designed to address these deficits. Additionally, ongoing VR technological developments may deliver increasing affordability and portability in terms of VR treatment options, particularly regarding head-mounted display units. A cyberpsychological consideration of the problem of PTSD, that is, an inter-disciplinary approach combining technology and psychology learning’s may merit consideration. A review of findings suggests that research protocols focused on olfaction as a variable in a multi-sensory VR exposure therapeutic program may positively impact on treatment outcomes in PTSD population.