Advanced medical simulation has become widespread. One development, the adaptation of simulation techniques and manikin technologies for portable operation, is starting to impact the training of personnel in acute care fields such as emergency medicine (EM) and trauma surgery. Unencumbered by cables and wires, portable simulation programs mitigate several limitations of traditional (nonportable) simulation and introduce new approaches to acute care education and research. Portable simulation is already conducted across multiple specialties and disciplines. In situ medical simulations are those carried out within actual clinical environments, while off-site portable simulations take place outside of clinical practice settings. Mobile simulation systems feature functionality while moving between locations; progressive simulations are longer-duration events using mobile simulations that follow a simulated patient through sequential care environments. All of these variants have direct applications for acute care medicine. Unique training and investigative opportunities are created by portable simulation through four characteristics: 1) enhancement of experiential learning by reframing training inside clinical care environments, 2) improving simulation accessibility through delivery of training to learner locations, 3) capitalizing on existing care environments to maximize simulation realism, and 4) provision of improved training capabilities for providers in specialized fields. Research agendas in acute care medicine are expanded via portable simulation's introduction of novel topics, new perspectives, and innovative methodologies. Presenting opportunities and challenges, portable simulation represents an evolutionary progression in medical simulation. The use of portable manikins and associated techniques may increasingly complement established instructional measures and research programs at acute care institutions and simulation centers.