Background-Limited penetration into the caval wall is an important securing mechanism for inferior vena cava (IVC) filters; however, caval penetration can also cause unintentional complications. The aim of this study was to assess the incidence, severity, clinical consequences, and management of filter penetration across a range of commercially available IVC filters. Methods and Results-The MEDLINE database was searched for all studies showed evidence of organ/structure involvement. Among patients with penetration, 8% were symptomatic, 45% were asymptomatic, and 47% had unknown symptomatology. The most frequently reported symptom was pain (77%, 108 of 140). Major complications were reported in 83 patients (5%). These complications required interventions including surgical removal of the IVC filter (n=63), endovascular stent placement or embolization (n=11), endovascular retrieval of the permanent filter (n=4), and percutaneous nephrostomy or ureteral stent placement (n=3). Complications led to death in 2 patients. A total of 87% of patients (127 of 146) underwent premature filter retrieval or interventions for underlying symptoms or penetration-related complications. Conclusions-Caval penetration is a frequent but clinically underrecognized complication of IVC filter placement.Symptomatic patients accounted for nearly 1/10th of all penetrations; most of these cases had organ/structure involvement. Interventions with endovascular retrieval and surgery were required in most of these symptomatic patients.