Injection molding (IM) is a widely used manufacturing technique for thermoplastic materials. Typically, injection molding tools are made of metals such as steel or aluminum. The process to design and manufacture the metallic tooling is time consuming and requires a large capital investment. In the current work, the effect of changing the mold tool material from traditional metals to plastic materials that are produced via additive manufacturing (AM) is investigated. Two plastic mold materials viz. ULTEM 1010 and HI-TEMP 300 AMB produced via the fused deposition modeling (FDM) and stereolithography (SLA) additive manufacturing processes respectively were studied. A Machined 6061 aluminum mold tool was used as the base mold tool material. The thermoplastic material injected is Polypropylene (PP) because it is one of the most widely used thermoplastics for injection molding. The injection molding processing parameters needed minimal changes to produce acceptable moldings with no defects. The density, tensile properties, and percent crystallinity of the moldings showed no significant change when the metallic mold tool was replaced with the AM mold tools. The shore D hardness decreased by 8% and 5% when the ULTEM 1010 and HI-TEMP 300 AMB tools were used. The tangent bending modulus decreased by 17% when the AM mold tools were used. Shrinkage of the parts made by the ULTEM 1010 and HI-TEMP 300 AMB mold tools increased by 2.2% and 2.9% respectively. The AM mold tools used for PP injection molding can be used in place of traditional metallic molds for low volume production without showing large drops in material properties.