The chemistry and structure–property relationships of precursor materials for carbon fibre manufacture have been and still are extensively studied. However, no detailed studies are available in literature that compare different types of precursors on a continuous process scale and how they may affect energy demand, environmental impact and cost. An in-depth understanding of the effect the precursor material has on the selection of process parameters and resulting carbon fibre properties, energy demand, environmental impact and how these factors influence each other can provide new insights into process optimization and cost saving potentials for carbon fibre. This chapter analyses three different precursor materials and compares the differences in manufacture, the related environmental impact as well as the resultant carbon fibre.