During coronary artery angiography, a catheter is used to inject a contrast dye into the coronary arteries. Due to the anatomical variation of the aorta and the coronary arteries in different humans, one common catheter cannot be used for all patients. The cardiologists test different catheters for a patient and select the best catheter according to the patient's anatomy. To overcome these problems, we propose a computer-aided catheter selection procedure. In this thesis we present our approach for patient specific optimal catheter selection for the angiography of the coronary arteries with high take off. It involves segmentation of the aorta and coronary arteries, finding the centerline and computing some geometric parameters. These parameters include computing coronary arteries curve angle (CACA), distance of the ostium from the aortic valves (DOAV) and the aorta diameter (AD) near the ostium. We then consider catheters and compute the tip angle of the catheter (CTA), catheter curve two depth (CC2D) and catheter curve two width (CC2W). We then compare CACA with CTA, DOAV with CC2D, AD with CC2W and suggest a catheter that is the closest to the patient’s arteries geometry. This solution avoids testing of many catheters during catheterization. The cardiologist already gets a recommendation about the optimal catheter for the patient prior to the intervention.