Over the last ten years, transradial cardiac catheterization has been increasingly applied, primarily because of its lower incidence of complications compared to the femoral approach. However, one of the greatest flaws of the transradial approach is a relatively high incidence of catheterization failure (1-5%). Anatomic variations of the radial artery are ranked second among the reasons for this. Previous studies have not provided unambiguous data on the frequency of these anomalies. It is therefore the aim of this study to determine the frequency of anatomic variations using routine angiographies of the radial artery (RA) during left heart catheterization. This is a retrospective study involving the examination of 602 images of routine angiographies of the radial artery performed during cardiac catheterization. The frequency of anatomic variations of RA was 8.8%, exclusive of tortuosities whose frequency was 12.7%. The most frequent anatomic variation was the high origin of the radial artery, found in a total of 31 (5.1%) subjects. Radioulnar loops, being one of potential contraindications for the procedure, were reported in 2% of the cases. Regression analysis revealed that the age (p<0.001), female sex (p=0.015) and high origin (p=0.034) statistically significant contributed to the development of tortuosity. The results indicate that the incidence of tortuosity increases linearly with age. Although this is not a contraindication for continuing with the procedure, we recommend that elderly patients have angiography performed at the beginning of the procedure due to the higher frequency of tortuosity.