In this study, wear behavior of Poly Lactic Acid (PLA) parts manufactured by one of the additive manufacturing techniques Fused Deposition Modelling (FDM) is investigated and modelled via linear and non-linear identification. Transfer Function, Process Model and Nonlinear Autoregressive with Exogenous Input (NARX) model are used as modelling. Identified wear models are established according to wear tests conducted on Pin-on-disc test apparatus under constant load and constant sliding distance. Two different manufacturing orientations are chosen for the PLA pin specimens and wear tests are performed against steel and cast iron discs. Obtained results from the identified models are compared with the experimental results to select most efficient and reliable model structure.