Polymers and polymer composites are used in a wider and wider variety of applications. More recently, the demand for polymeric micro-components is increasing for applications in several industrial fields, such as biomedical, electronics, optics and high-precision mechanical industry. Additive manufacturing (AM) technologies are becoming more and more mature and consolidated for the manufacturing of high performance functional prototypes. Among them fused deposition modelling (FDM) has become one of the most important AM technology due to its capability to produce functional prototypes with complex shape compliant with industrial applications in a cost effective way. However, industrial full-scale applications have still not gained much emphasis because of compatibility of available materials with AM technologies. Two approaches have been proposed to overcome this limitation: the development of new materials having superior characteristics but still compatible with the technology and the control of the process parameters during fabrication to improve the part properties. In this study, the dimensional and geometrical accuracy and the mechanical behaviour of miniaturized specimens produced by FDM have been studied in relation with the process parameters in order to identify the most influential parameters and optimize their effects on the component properties. The results have been used as starting point for a comparison between FDM and injection moulding. The latter is a well-known industrial process for the fabrication of a wide variety of products, also with micro dimensions features. The comparison has been done from both technical and economical point of view to highlight advantages and disadvantages of the technologies and make a complete quantitative comparison.