The optimization of injection molding process variables is important to minimize the number of final parts with defects, the cost and injection time. Among all the defects, shrinkage stands out for its important impact, since it causes the injected part to undergo dimensional changes during the cooling and post-processing stage. One of the factors influencing shrinkage is molecular orientation, as the injection phase imparts a predominant orientation to the polymer chains due to flow. This study presents the influence of polymer flow along the part on molecular orientation by varying injection cycle parameters, such as mass temperature, pressure, and injection time. The crystalline lamella orientation in a semicrystalline polymer like polypropylene (PP) was analyzed using wide-angle X-ray scattering (WAXS) technique. The WAXS images indicate the periodicity of the lamellar structures in which polymer chains of crystalline and amorphous phases are stacked. The results showed that molecular orientation is higher at the entry of the specimen and decreases along its length. Regarding the manufacturing process parameters, mass temperature is the most significant factor in molecular orientation, promoting its alignment.