Natural fibres are emerging as low cost, lightweight and environmentally superior alternatives to glass fibre in composites. Plant variety, climate conditions and extraction methods in the production of natural fibres introduce variabilities to fibre properties that are fundamentally important to the resultant composites. This paper presents an overview of the most commonly used natural fibres, their extraction, characterisation, treatments to improve fibre performance, textile processes to prepare preforms, composite manufacture and mechanical properties, and life cycle analysis. A particular emphasis is placed on fibre architecture, including the methods to manipulate fibre orientation in the preforms and the influences of preform characteristics on composite processes and product performances.