PURPOSE: To evaluate the efficacy of radial artery cannulation with needle versus cannula over needle during transradial coronary angiography and intervention.METHODS: Five hundred patients scheduled to undergo transradial catheterization were randomized between the two methods. Primary endpoint of the study was the combined endpoint of switching to another access site due to inability of successful sheath insertion or switching to another method of cannulation (from needle to cannula over needle and vice versa).RESULTS: The primary end point was met in 12 patients (4.8%) from the needle group and 14 patients (5.6%) from the cannula over needle group (p=0.695). There were no differences in switching of cannulation method [10 (4.0%)% versus 11 (4.4%), p=0.831], switching of access site [6 (2.8%) versus 9 (3.6%), p=0.441), time for artery cannulation [1.20 (0.80-2.20) min versus 1.26 (1.01-2.39) min, p=0.152], total procedure time [15.05 (9.47-29.03) min versus 19.14 (10.13-32.02) min, p=0.112] number of attempts [2 (1-4) versus 2 (1-5), p=0.244] and number of skin punctures [1 (1-2) versus 1 (1-2), p=0.399] before successful radial artery cannulation. There were no differences recorded in the safety endpoints of EASY grade III or more radial hematomas [2 (0.8%) versus 1 (0.4%), p=1.000] or the incidence of radial artery occlusion after the procedure [9 (3.6% versus 16 (6.8%), p=0.358].CONCLUSION: Radial artery cannulation with needle and cannula over needle seems to be equal in terms of efficacy and safety.