Aim: To create a synthetic nanofibrous dural substitute that overcomes the limitations of current devices by enhancing dural healing via biomimetic nanoscale architecture and supporting both onlaid and sutured implantation. Materials & methods: A custom electrospinning process was used to create a bilayer dural substitute having aligned nanofibers on one side and random nanofibers on the other. Nanoscale architecture was verified using microscopy and macroscale mechanical properties were investigated using tensile testing. Biological response to this device was investigated both in vitro and in a canine duraplasty model. Results & conclusion: Bilayer nanofiber alignment yields a graft having anisotropic mechanical properties with significantly higher strength and suturability than a commercially available collagen matrix. When implanted, the nanofibrous graft prevents leaks and-brain tissue adhesions, and encourages dura mater regrowth, performing comparably to the collagen matrix. Both in vitro fibroblast orientation and in vivo dural healing are enhanced by the aligned nanofibers.