Additive manufacturing technologies enable the production of plastic components with complex geometries that cannot be realized by conventional mold-based methods in small production lots. The combination of design freedom with sufficient mechanical properties enables the cost-efficient production of functional prototypes. In order to elevate 3D printing from a “rapid prototyping” to a “rapid manufacturing” technique for serial products, the fatigue behavior of 3D-printed parts has to be deeply understood. Hence, the aim of this study is to analyze the fatigue properties of 3D-printed ABS parts to evaluate the lifespan in daily use in comparison to injection molded (IM) parts. For this purpose compact tension (CT) samples, manufactured by Fused Filament Fabrication (FFF) and Arburg Plastic Freeforming (APF), were analyzed under dynamic mechanical load and compared to IM samples by investigating the fatigue crack propagation (FCP) behavior. Using microscopic analysis of the fracture surface, characteristic regions of the crack path are investigated in detail in order to identify predominant crack mechanisms. It can be concluded that the crack propagation rate is quite similar for FFF and IM specimens. The stress intensity factor at which the crack growth is initiated (Kth) is on the same level as for IM samples. These findings are proven by the corresponding fracture surfaces, which reveal a homogenous material structure in both cases. APF samples show a slightly slower crack propagation speed compared to IM and FDM samples. Analysis of fracture surfaces indicates, that the lower propagation rate is induced by a high porosity of more than 5 %, which causes multiple crack branching. The evaluation of the FCP behavior in 3D-printed polymer structures reveals the potential of 3D printing with regards to its development from a “rapid prototyping” to a “rapid manufacturing” technique for technical products.