Chain architecture is an influential parameter in melt processing of polymeric materials. In this work, branched poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) were prepared by ring opening polymerization and blended with a commercial linear PLLA. The objective was to evaluate the modification role of branching and stereocomplex crystal formation between PLLA and PDLA chains on melt rheological properties and processability of linear PLLA. Characterization of blends in shear and extensional flows revealed higher shear and elongational viscosities as well as intensified shear thinning and strain hardening behavior for modified systems in comparison to linear PLLA. Especially, branching through stereocomplex crystal formation between stereochemically different chains remarkably improved rheological properties of linear PLLA at a low concentration of PDLA. Furthermore, the processability of the modified blends was examined in a series of film blowing process experiments at different blow up ratios (BUR) and take up ratios (TUR); with the aim to expand the film blowing processing window toward higher BUR and TUR values. Modified blends showed an expanded operating window in comparison to the reference commercial resin; with highest BUR and TUR achieved for PLLA/PDLA blends. On the other hand, films prepared form PLLA/PDLA blends were translucent due to the initial presence of stereocomplex crystals. Effect of processing conditions on chain orientation was evaluated by XRD analysis. In addition, mechanical and crystallization properties of the produced films were investigated, revealing the effect of structure modification and chain orientation on final film properties. Both TUR and stereocomplex crystals increased tensile strength of the films and reduced their cold crystallization temperature.