In the years since the introduction of outpatient cardiac catheterization and coronary angiography, the indications for the use of these procedures have expanded rapidly with advancements in surgical and endovascular procedures. The safety of outpatient coronary angiography has been well established, comparing very favorably with that of inpatient procedures. At present, a variety of different outpatient facilities exist. Catheterization laboratories may adjoin a hospital or be free-standing; the safety and success of procedures performed in mobile cardiac catheterization laboratories has also been described. There are a variety of access techniques for cardiac catheterization in use today, and there are many types and sizes of catheters available. Miniaturization of equipment has reduced complications and allowed early ambulation and discharge from outpatient laboratories. In addition, the development and refinement of catheters and techniques for achieving hemostasis may allow further reductions in patient stay and complications. The complication rates of outpatient cardiac catheterization and coronary angiography are, in fact, quite low--in some cases, lower complication rates are seen in the outpatient population than in the inpatient population. Although this is certainly related in part to the fact that outpatients generally have more stable disease, it is clear that careful equipment choices, proper technique, and adequate monitoring have contributed to the success of these important outpatient procedures.