Fabrication of nonlinear elastic materials that resemble biological tissues remains a challenge in biomaterials research. Here, a new fabrication protocol to produce elastomeric fibrous scaffolds was established, using the core/shell electrospinning technique. A prepolymer of poly(xylitol sebacate) with a 2:5 mol ratio of xylitol:sebacic acid (PXS2:5) was first formulated, then co-electrospun with polyvinyl alcohol (PVA - 95,000 M-w). After cross-linking of core polymer PXS2:5, the PVA shells were rinsed off in water, leaving a porous elastomeric network of PXS2:5 fibres. Under aqueous conditions, the PXS(2:)5 fibrous scaffolds exhibited stable, nonlinear J-shaped stress-strain curves, with large average rupture elongation (76%) and Young's modulus (similar to 1.0 MPa), which were in the range of muscle tissue. Rupture elongation of PXS2:5 was also much higher when electrospun, compared to 2D solid sheets (45%). In direct contact with cell monolayers under physiological conditions, PXS2:5 scaffolds were as biocompatible as those made of poly-L-lactic acid (PLLA), with improvements over culture medium alone. In conclusion, the newly developed porous PXS2:5 scaffolds show tissue-like mechanical properties and excellent biocompatibility, making them very promising for bioengineering of soft tissues and organs. (C) 2014 The Authors. Published by Elsevier Ltd.