Hemp (Cannabis sativa L.) is a high yielding bast fibre and environmentally-friendly crop that produces biomass of excellent quality for multiple purposes. Hemp fibre has the capacity to replace non-renewable and unsustainable resources, such as synthetic and mineral fibres. However, the molecular knowledge of fibre quality from hemp is limited. This PhD thesis focuses on the characterization of a diverse collection of hemp accessions for multiple agronomic traits, such as flowering and morphology of the stem, and fibre quality with emphasis on cell wall composition. The genetics underlying these quantitative traits have been characterized, providing guidelines and molecular tools to improve breeding programmes for this bast fibre crop.