In the past decade, considerable effort has been made to construct biomimetic scaffolds from electrospun nanofibers for engineering different tissues. However, one of the major concerns with electrospun nanofibrous scaffolds is that the densely arranged architecture of fibers and small pores or voids between fibers hinder efficient cellular infiltration or prevent three dimensional (3D) cellular integration with host tissue in vivo after implantation. To overcome this problem, many concepts or strategies applicable during the electrospinning or post-electrospinning procedures have been proposed to enlarge pore size of electrospun scaffolds. This article addresses the issues of pore geometry and cellular infiltration of electrospun scaffolds, and first reviews the fabrication solutions/approaches applied to achieve larger micropores in electrospun mats. The evidence and potential for fostering cellular infiltration using these improved porous scaffolds are then discussed. Finally, it is hoped that this will enable us to better exploit viable technologies or develop new ones for constructing ideal nanofibrous architecture for fulfilling specific tissue engineering needs.