Tension pneumothorax is the second leading cause of preventable combat death. Although relatively simple, the management of tension pneumothorax is considered an advanced life support skill set. The purpose of this study was to assess the ability of non-medical law enforcement personnel to learn this skill set and to determine long-term knowledge and skill retention. After completing a pre-intervention questionnaire, a total of 22 tactical team operators completed a 90-minute-long training session in recognition and management of tension pneumothorax. Post-intervention testing was performed immediately post-training, and at one- and six-months post-training. Initial training resulted in a significant increase in knowledge (pre: 1.3 +/- 1.35, max score 7; post: 6.8 +/- 0.62, p < 0.0001). Knowledge retention persisted at one- and six-months post-training, without significant decrement. Non-medical law enforcement personnel are capable of learning needle decompression, and retain this knowledge without significant deterioration for at least six months.