Melt processing of poly(lactic acid) (PLA) is challenging due to its low melt strength and viscosity. In this work, two strategies were explored to improve the rheological properties and processability of PLA in the film blowing process. In the first approach, modification was done through changing polymer chain architecture. Branched poly(L-lactic acid)s (PLLA) with different chain architectures, i.e. star shaped, comb like and hyper branched chains were synthesized by ring-opening polymerization of L-lactide and blended with a commercial linear PLLA up to 30%. The second approach was based on the formation of stereocomplex structure between enantiomeric PLA chains. Poly(D-lactic acid)s (PDLA) were synthesized in similar branched architectures using D-lactide and blended with the linear PLLA up to 10%. Rheological properties of the blends were studied in small amplitude oscillatory shear flow using parallel plate geometry and in elongational flow using SER geometry. Characterizations in shear mode showed that PLA blends had higher complex viscosity and elastic modulus compared to the linear one and demonstrated a more pronounced shear thinning behavior. In the second strategy when small amounts of branched PDLAs were incorporated to linear PLA, due to the co-crystallization of PLLA and PDLA chains, a much more significant increase in complex viscosity and shear thinning was observed. Moreover, extensional rheometry revealed that both strategies were effective to improve PLA’s elongational properties. Although commercial PLA showed a linear viscoelastic behavior, all blends showed significant strain hardening response. Accordingly, the commercial PLA and the prepared blends were examined in a series of film blowing experiments to determine the operating window. It was revealed that both investigated rheological property modification strategies were beneficial to increase the bubble stability and push the limits of blow up ratio and take up ratio to higher values.