Industrial hemp fibre was treated with alkali and the influence of this treatment on interfacial shear strength (assessed using the single fibre pull-out test) and composite strength with an epoxy resin, over a range of epoxy resin to curing agent ratios, was investigated. Scanning electron microscopy was conducted to assess the fracture behaviour of the composite tensile test specimens. It was found that alkali treatment increased the interfacial shear strength and composite tensile strength, Young’s modulus and elongation at break. The highest tensile strength was obtained with an epoxy resin to curing agent ratio of 1:1 while the best Young’s modulus was achieved with a resin to curing agent ratio of 1:1.2.