In this study, the tensile and fracture behavior of polylactic acid (PLA)/ thermoplastic corn starch (TPS) filled with halloysite nanotubes (HNTs) was investigated. Adding TPS noticeably decreased the tensile strength and modulus, but increased the elongation at break. Adding TPS to 60 wt% reduced the tensile strength and modulus by 61% and 92%, respectively, but increased the elongation at break by 77%. Adding HNTs in PLA/ TPS improved the tensile modulus, but diminished the elongation at break and tensile strength. Analysis of the fracture behavior was performed by the essential work of fracture (EWF) method. The results revealed that adding 20 wt% of TPS to PLA increased EWF and non-EWF by 298% and 109%, respectively. According to the desirability function, the best strength, stiffness, and toughness balance were obtained for the sample containing 20 wt% of TPS and 1 wt% of HNTs.