Dose-area product (DAP) measurements were conducted for 168 coronary angiography (CA) and 89 single vessel percutaneous transluminal coronary angioplasty (PTCA) to examine the factors influencing patient dose beyond the X-ray exposure parameters. It was found that for CA, the DAP increases with the number of catheters used and with the number of vessels with stenosis. DAP values for patients with a prior bypass surgery, were higher compared to those without such a medical record to surgery. In PTCA, the use of coronary stents did not enhance the patient radiation dose significantly. Noticeable differences were found in the percentage contribution of each projection to the total DAP between the three types of single vessel PTCA. Finally low variations in DAP were found among the cardiologists performing both procedures.