This work is concerned with improving nonwoven scaffold design for the tissue engineering of the anterior cruciate ligament. When designing a scaffold two important design criteria to consider are scaffold's internal structure and biocompatibility, both of which are addressed in this paper. The role of a scaffold is to provide a framework for cells to attach, proliferate and secrete extra cellular matrix. The scaffold also acts as a template, directing the growth of cells and newly formed tissue. It is the scaffold's internal structure, together with polymer surface chemistry and morphology, which directly influence the cellular activities that lead to tissue formation. With regard to scaffold's internal structure, structural parameters are discussed in relation to specific scaffold function; for example the effect of scaffold pore-size on cell proliferation, migration and nutrient supply. Another structural factor discussed is the role of fibre orientation as a means of guiding and organising new tissue growth. With the aim of creating a scaffold of optimum design, for the tissue engineering of the anterior cruciate ligament, nonwoven scaffolds of differing structure have been constructed. In order to understand the relationship between manufacturing method and scaffold structure characterisation techniques have been employed to analyse the structural parameters of these scaffolds. Obtained scaffold structural properties are discussed in relation to manufacturing method. Regarding the second scaffold criteria biocompatibility tests have been conducted by the authors on a range of generic fibre types. The results of these tests are provided in the form of cell attachment, with reference to fibre morphology.