BACKGROUND Navigable, large diameter aspiration catheters demonstrate markedly improved recanalization rates over smaller lumen devices in suction embolectomy. We evaluated the performance of a novel aspiration catheter system designed to maximize lumen size, and compare it to other commercially available aspiration catheters. METHODS The 6F R4Q aspiration catheter system comprises a proximal pusher wire of 117 cm length connected to a distal catheter of 25 cm length. When placed through standard guide catheters and into the cerebral circulation, the proximal catheter makes a tight seal between its outer surface and the guide catheter's inner surface. During aspiration, in vitro flow rates and tip suction force under gentle retraction were compared among 10 commercially available aspiration catheters and the R4Q system. RESULTS The R4Q 6F, 5F, 4F, and 3F catheters achieved flow rates at least 21.9%, 24.7%, 61.9%, and 244.7% greater than the other catheters tested respectively and the R4Q 6F produced a 140.2% higher tip force than a catheter of similar size. Fluid flow rate in the R4Q 6F increased on retraction into the guide catheter, delivering a 58.2% increase from fully extended to fully retracted. CONCLUSIONS The R4Q design demonstrates a substantial increase in aspirated flow rate and suction force due to an increased effective diameter than standard tubular catheter designs tested. The prominent increase in the aspiration parameters measured in vitro supports the potential for improved clinical results during stroke thrombectomy procedures.