The growing search for biodegradable products contributes to the development of new materials. In this work, the effect of the Joncryl® ADR chain extender on poly(butylene adipate‐co‐terephthalate)/poly(lactic acid) blends was investigated. The mechanical, thermal, and morphological properties and the contact angle of the blends were also studied. The addition of the chain extender can either improve the adhesion between the phases or act as a stress concentrator, depending on the proportion of PLA present in the blend. However, in all samples, the elongation at break was increased. This behavior is also observed in the morphology of the blends, changing the shape of the PLA particles, from spherical to ellipsoid phase. However, in the proportion used (0.5 wt%), the chain extender was not enough to increase the adhesion between the phases of the blends, just the dispersion of the PLA particles. Besides, it is possible to observe that the higher the PLA content in the PBAT mixture, the lower wettability surface of the blends is reached.