Fused deposition modeling (FDM) is a rapidly growing additive manufacturing technology due to its ability to manufacture complex‐shaped parts in a simple process. FDM parts present inherent porosity due to the fabrication process. The mechanical performance of the built part depends on controlling several printing parameters of the specimen and the quantity of voids. PLA/PBAT [polylactic acid/poly(butylene adipate‐co‐terephthalate)] blend is a biodegradable polyester with bio‐based content that is used as a potential replacement for conventional petroleum‐based polymers. PBAT reduces the stiffness and improves the tear strength of PLA. There is a lack of research on PLA/PBAT 3D printed parts, especially the relationship between flexural mechanical properties and porosity of PLA/PBAT parts. The aim of this work is to investigate the effect of layer thickness (LT), deposition speed (DS), and printing direction (PD) on porosity and flexural properties of PLA/PBAT blend parts. Experimental design method is used to identify the set of parameters, which gives optimized results. Specimens fabricated with lower printing parameter values allowed obtaining parts with less porosity and consequently improved bending properties.