Background: Penetrating injury can encompass a large spectrum of injuries dependent on the penetrating object, the location of entry, and the trajectory of the object through the human body. Therefore, the management of penetrating injuries can be challenging and often requires rapid assessment and intervention. No universal definition of penetrating injury exists in the literature and little is known about the demographics and outcome of penetrating injury in the Netherlands. Objective: A research was carried out to ascertain the size and outcome of penetrating injuries in two level-one trauma centers in the Netherlands. Methods: Using the trauma registry of the Radboud University Medical Center in Nijmegen and VU University Medical Center in Amsterdam, all patients with penetrating injury were identified who were admitted to these level 1 trauma centers in the period between January 1, 2009, and January 1, 2014. Penetrating injury was defined as an injury that caused disruption of the body surface and extended into the underlying tissue or into a body cavity. Data concerning age, gender, mechanism of injury, Glasgow Coma Scale, number of injuries, type of injury, and Injury Severity Score were collected and analyzed. Patient results were stratified by Injury Severity Score. Results: In total, 354 patients were identified, making up around 2% of all admitted trauma patients 3.1% (VU Medical Center) and 1.6% (Radboud Medical Center). Patients were overwhelmingly male (83.1%) and median age was 36 years (range = 1–88 years). Most injuries were caused by stabbings (51.1%) followed by shootings (26.3%). Admission to the intensive care unit occurred in 41.1% of all patients. Median stay in the intensive care unit was 5.1 days (range = 1–96 days) and median total hospital stay was 8 days (range = 1–95 days). Mortality among these patients was 7.1%, ranging from 0% among patients with Injury Severity Score 1–8 to 100% in patients with Injury Severity Score > 34. High mortality figures were associated with injuries caused by firearms (19.4%), injuries to the head (27.9%), and alleged assaults (10.9%). Differences in demographics between the two centers were not significant. Conclusion: Penetrating injury is a relative rare occurrence in the Netherlands compared with other countries. It is associated with high mortality and substantial hospital costs. The incidence of penetrating injuries is higher in metropolitan areas than in rural areas. A universal definition of penetrating trauma should be agreed upon in order to ensure that future studies remain free of bias, and also to ensure that data remain homogeneous.