Semi-consolidated thermoplastic tapes were produced by spreading flax and polypropylene matrix fibres using a newly developed technology. This lightweight tape was structurally stable and contained 38% flax fibres by volume. The tapes were processed in unidirectional and woven fabric format for composite fabrication. Hot pressed moulded thermoplastic laminates were fabricated and their properties were compared to those of flax/PP yarn based thermoplastic composites with equivalent fibre content. We found that the flax/PP tape-based composites had less void content, 60-110% higher flexural modulus and 35-65% higher tensile modulus compared to flax/PP yarn based thermoplastics. Thermoanalytical results showed that the heating conditions used in the tape-making process did not degrade the flax fibres and PP matrix. We conclude that such semi-consolidated flax/PP tapes enable the achievement of properties not seen before for yarn-based composites, and therefore are an important step forward in optimising the reinforcing effect of natural fibres in composite applications.