Numerous processing parameters combined with long-duration fatigue tests pose a major challenge when assessing the fatigue parameters of 3D-printed structures. In this research, a fatigue-testing method is introduced where sample is excited with random-signal profile enclosing sample’s natural frequency. The innovative sample design is tailored for 3D-printing and is frequency-tuneable. The proposed approach results in significantly shorter fatigue tests due to higher loading frequency and simultaneous testing of multiple samples. Additionally, tracking of sample’s natural frequency and damping during fatigue tests is applicable. The proposed method was experimentally verified on PLA samples; obtained results were comparable with the available literature.