Nowadays the technologies originally developed only for prototype production are involved among modern production techniques. This trend is induced mainly by developing of new materials and very effective improvement of rapid prototyping production methods and tools. The resulting mechanical properties of the products are now fully comparable with the properties of parts produced with using the technologies modified for batch production (e.g. injection moulding or blow moulding etc.). This article deals with comparing the flexural and tensile properties of specimens produced by injection moulding technology and by FDM technology, particularly using three different 3D printers (Dimension SST 768, Fortus 450 and Rep Rap). The part orientation within the build envelope of selected FDM machines is another aspect that was evaluated and that had significant impact on part behaviour of printed parts. All the analysed specimens were made of thermoplastic ABS.