Percutaneous right brachial artery approach with 5F catheters for studying coronary artery disease. We prospectively studied 60 ischemic patients with 5F catheters (Pigtail and Amplatz) using the percutaneous right brachial artery approach (group I), in order to compare this technique with two groups of 100 patients each randomly studied by the femoral route with either 5F (group II) or 8F (group III) catheters (Pigtail and Judkins). The following parameters were analyzed: need to change the initially elected catheter diameter or/and artery approach; technical difficulty for obtaining LV, LCA, and RCA angiograms; total time of X-ray exposure; quality image of LV, LCA, and RCA angiograms; incidence of arterial puncture related hematomas or total arterial occlusion; and duration of local compression after sheath removal. There were no differences between 5F brachial and femoral approaches except for the arterial compression time (p less than 0.01) and the X-ray exposure time (p = 0.03) which were longer with the brachial approach. Whatever the route used, 5F showed a mild increase difficulty (brachial p = 0.001; femoral p = 0.01) and a mild decreased quality image for LCA (branchial p = 0.006; femoral p less than 0.05). Mild hematomas were more frequent with 8F catheters (p less than 0.05). The procedure could be completed by the elected first artery and type of catheter (5F or 8F) in 57/60 patients in group I, in 95/100 in group II, and in 96/100 in group III (nonsignificant differences). Thus, the percutaneous right brachial artery approach using 5F catheters is similar to the femoral artery approach with the same catheters. Although both of them showed a mild increased technical difficulty and a mild decreased quality image compared to 8F, mainly for LCA angiograms, they allowed complete and reliable angiograms reading and analysis. 