Additively manufactured/printed represent a high potential for their use in various branches of technical practice. However, their applicability requires knowledge of the maximum application limits, or the intensity of their damage due to external factors. This article investigates the testing of 3D printed materials produced via Selective Laser Melting (SLM) treated by an ultrasound excited pulsating water jet (PWJ). The study focuses on two frequencies, 20 kHz and 40 kHz, applied to AISI 316L stainless steel and AlSiMg10 aluminium alloy. The time exposure ranged from 0.5 seconds to 10 seconds, with increments of 0.5 seconds. The water jet was pressurized to 40 MPa using a high-pressure pump, and a nozzle with a diameter of 0.4 mm was employed. The primary objective of this research is to explore the effects of ultrasonic excitation on the erosion characteristics and surface integrity of SLM-manufactured materials. The results showed that both the time exposure and the modulation frequency play vital role in determining erosion depth. Also, the surface conditions of the material are significant in erosion magnitude. Therefore, by systematically varying the exposure time and frequency, the study provided a comprehensive understanding of how these parameters influence the erosion evolution and performance of the tested materials.