Membranes used for pressure-retarded osmosis (PRO) are required to be mechanically strong due to high external hydraulic pressures on the draw solution (DS) side. In this study, a series of nonwoven fabrics of varying thickness, density, and hydrophilicity were used to fabricate reinforced aliphatic polyketone (PK) membranes with excellent mechanical strength and pressure resistance. Three suitable nonwoven fabrics are selected based on the integrities of the PK layers formed on their surfaces. As a result, guidance for choosing suitable reinforcing materials for PK membranes is provided. We show that a PK-based thin-film-composite (TFC) membrane reinforced by an 11-mu m-thick polyester (PET) nonwoven fabric provides a flux of 24.7 L m(-2) h(-1) (in "active layer facing feed solution", AL-FS mode, 0.6 mol L-1 NaCl as the DS), while maintaining a pressure resistance of 28 bar. This membrane is shown to be capable of producing a power density of at least 6.1 W m(-2) in PRO evaluation (with 0.6 mol L-1 NaCl).