Background: Patient provision of informed consent is foundational to medical decision- making. However, clinical informed consent is not as well studied as consent for research. Cardiac catheterization (CC) is a complex medical procedure with many potential variations, making informed consent challenging. Objective: To determine patient and provider attitudes toward the informed consent process for CC and to test a new measure for measuring patient capacity to consent for CC. Design: A mixed methods pilot study. Setting: Academic medical center. Participants: 8 patients who consented for non-emergent CC, cardiology fellows and faculty (21 surveyed, 7 interviewed). Measurements: Patients and providers underwent semi-structured interviews, which were qualitatively coded for themes. Patients completed an instrument designed to measure capacity to consent for CC. Providers completed a survey to gauge attitudes about the consent process for CC. Results: Most patients (75%) did not meet the 70% performance testing for capacity derived from a provider survey as a minimum for providing consent. Patients did not view the consent discussion as part of medical decision-making. In emergent situations, patients requested that providers apply pressure to convince patients to undergo necessary procedures. Providers believed proper informed consent was important, but admitted to less emphasis in emergencies, and they often used family to help patient consent in such situations. Patient and providers described common themes in informed consent. Conclusions: The instrument developed herein for measuring capacity to consent for CC has promise for providing valid and reliable data. Most patients tested did not have capacity by criteria set by providers, suggesting that the informed consent process was inadequate. Patients and providers expressed a role for applying pressure to convince patients to consent to emergent procedures.