The assessment of training effectiveness for virtual-training systems is best accomplished with two complimentary approaches: experimentation and post-fielding assessment. Obviously, experimentation involves the controlled assessment of system capabilities that should have an impact on training. By contrast, a post-fielding assessment determines the practical advantages and limitations of the system in the context of mission training and can be used to discover ways to increase system utilization and effectiveness. This paper reports the results of a post-fielding assessment of the U.S. Army's recently fielded dismounted infantry simulator: Dismounted Soldier Training System (DSTS). The goal of the assessment was to collect input on DSTS training effectiveness and training issues from Leaders and Soldiers who have used DSTS at home station. A total of 58 surveys and 122 interviews from Leaders (82), Soldiers (90), and DSTS Operators (8) were collected over six months from five U.S. Army installations. On the surveys, respondents indicated that DSTS is capable of providing a training environment for collective task training and assessment. The after action review (AAR) system, as a training tool, received the most positive responses. Respondents were equally vocal in identifying training distracters. Technical issues and simulator sickness were identified as causes of suspended training, while over half of the Soldiers reported less than a complete feeling of immersion. The interview responses echoed these themes and provided insights on effective planning, preparation, and execution of DSTS training. Overall, the results showed that dismounted infantry simulation showed promise as an effective training device. However, improvements to the technology were still needed to provide a reliable training environment. The results also highlighted the positive impact of effective AAR capabilities on training. Future development of dismounted infantry simulation training should formalize the unique AAR capabilities of the technology to provide formative feedback to Soldiers.