A clinical team decided to use a radial artery approach for cardiac catheterization in a woman with morbid obesity. It took multiple attempts to access her radial artery. After catheter insertion, she experienced pain and pressure in her arm and chest. Review of the angiogram demonstrated the presence of an air embolism in the left coronary artery, introduced during the catheter insertion. Due to the difficulty of the procedure, the technician had failed to hold the syringe at the proper angle and introduced an air bubble into the patient's vessel.