This presentation focuses on the design, fabrication, and experimental characterization of 3D-printed structured optical fibers for terahertz (THz) applications. Using FDM technology and cyclic olefin copolymer (COC), both photonic crystal fibers (PCF) and anti-resonant fibers (ARF) were successfully developed and tested. The results confirm the feasibility of low-cost rapid prototyping of THz waveguides, with structural geometry and fabrication precision identified as key factors influencing transmission performance.