A dual passageway breathing device is described. Embodiments of the dual passageway breathing device can be implemented with a cardiopulmonary resuscitation (CPR) mask. The dual passageway breathing device can allow a simulated rescuer and a simulated victim to use the CPR mask. For instance, the dual passageway breathing device can allow the simulated rescuer to practice exhaling into the mask without the simulated victim having to interface with the breaths. The dual passageway breathing device can also allow the simulated victim to breathe via the device while wearing the mask.