Tubularized porcine extracellular matrices (ECMs) are under investigation as adjuvant scaffolds for endovascular aneurismal repair (EVAR). Limitations with tubularized ECMs in this setting include difficulties in achieving a confluent endothelium on the scaffold's luminal surface prior to in vivo implantation. In this in vitro study a rotational “cell-seeding rig” (RCR) was constructed to assess the potential for endothelialization of tubular ECM constructs. Human aortic endothelial cells (HAECs) were cultured onto the luminal surfaces of tubular porcine urinary bladder matrix (UBM) scaffolds and rotated in the RCR at experimental rotational speeds. Results showed that endothelial attachment occurred at a rotation speed of six revolutions per hour. HAECs continued to proliferate after the initial attachment period of 24 h and formed a confluent endothelial monolayer after 14 days of growth. Our results demonstrate that RCRs facilitate attachment of HAECs in vitro at a speed of six revolutions per hour. The endothelialization technique presented in the current study may be important for advancing tissue-engineering approaches to address some of the current limitations in endovascular treatments of abdominal aortic aneurysms. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 781–788, 2014.