This study proposed a dielectric terahertz (THz) D-shape core based photonic crystal fiber (PCF) with very low level of effective material loss (EML) for efficient THz pulse propagation. The modal parameters of the proposed fiber have been rigorously computed using finite element method (FEM) by considering the absorption boundary condition (ABC) using perfectly matched layer (PML). Investigation results of the fiber exhibit a low material absorption loss of 0.027 cm⁻¹ and zero flatted dispersion within the 0.85–1.25 THz range. Additionally, large number of crucial features of the fiber have been evaluated. It reduces the bulk absorption loss of ~87% at the same time offers single mode operation. The proposed fiber can be easily fabricated by using stack and draw or sol-gel technique. Due to excellent optical guiding properties, it can be a potential prospect in THz sensing, communication and imaging applications.