A preceding article referred to the processing of various grades of isotactic polypropylene (iPP) and propylene/ethylene copolymers by conventional and shear-controlled orientation injection molding(SCORIM), and considered the mechanical properties of the molded polymers in relation to the processing conditions applied. This article is principally concerned with the morphology and phase relationships that apply in injection-molded iPP. The gamma-phase of isotactic polypropylene is reported to occur in moldings with pronounced molecular orientation. The presence of gamma-phase in injection moldings is indicative of enhanced Young’s modulus, and tensile strength provided that the melt has not been subjected to excessive deformation during processing. The common view that isotactic polypropylene exhibits only alpha- and beta-phases in commercially produced moldings is challenged. SCORIM moldings contain less beta-phase than conventional moldings, and exhibit greater overall crystallinity than moldings produced by conventional methods. The difference in the relative proportions of alpha-, beta-, and gamma-phases is marked and depends on processing conditions and the molding method. Shear-controlled orientation injection molding(SCORIM) results in more pronounced molecular orientation than conventional injection molding, which is consistent with the substantial increase in Young’s modulus of moldings produced by SCORIM. The improved mechanical properties of iPP moldings is attributed to shish-kebab morphology developed by the action of shear to the solidifying melt. A new model is proposed for the oriented region morphology in iPP injection moldings based on the results presented in this article.