The aim of this paper is to analyse the fatigue behaviour of an additively manufactured (AM) short glass fiber reinforced polymer. The material under investigation is a recycled mineral-filled polypropylene reinforced by means of short glass fibers. The specimens have been produced by using a Pellet-based Additive Manufacturing (PAM) system, which is basically a Fused Deposition Modelling (FDM) process in which the feedstock consists of pellets. The three infill patterns most commonly used in 3D printing were selected to produce dog-bone shaped specimens oriented with their axes parallel to the platform (i.e. orthogonal to the build direction). The fatigue behaviour of recycled 3D printed specimens was then compared to the results obtained from specimens made of the same material produced by injection moulding (IM). The effect of the recycling was studied only for the IM specimens by testing both the virgin and recycled compound. Finally, preliminary analyses of the macroscopic damage mechanisms were done by observing the fracture paths after fatigue failure.