In this letter, we present the design, fabrication, and characterization of a 3-D photonic crystal (PhC) waveguide based on an optimized woodpile structure operating in the millimeter-wave band. By carefully adjusting the size and shape of the air defect, a silicon electromagnetic bandgap (EBG) woodpile waveguide can be created: this dielectric waveguide supports a well-confined TE 10 -like mode. Numerical results for this structure have been obtained using the finite element method (FEM) simulation software Ansys HFSS and present very good agreement with the measured ones.