Fused deposition modeling (FDM) is one of the trendiest three-dimensional printing (3DP) technologies. However, FDM products based on virgin polyamide-6 (PA6) are seriously warped due to the accumulation of shrinkage stress generated from the crystallization of PA6. To solve this problem, maleic anhydride grafted poly(ethylene 1-octene) (POE-g-MAH) is added into PA6 to disturb the crystallization and reduce the shrinkage stress. Besides, rigid polystyrene (PS) with good flowability is further introduced to PA6/POE-g-MAH blend because too much addition of POE-g-MAH will weaken the PA6/POE-g-MAH, which will interrupt the printing process. The POE-g-MAH and PS both act as amorphous phase in the blends, which will reduce the shrinkage stress and is helpful to the shape stability of the printed products. Finally, a new kind of PA6-based filament with good toughness for FDM is prepared via this facile method. POLYM. ENG. SCI., 57:1322-1328, 2017. (c) 2017 Society of Plastics Engineers