Increasing longevity has been intensifying the number of hip replacements and the need for hip prostheses with improved lifespan. In this concern, the durability of these medical devices is strongly related to their mechanical properties, particularly their mechanical reliability (fracture toughness) in the case of ceramics. To enhance this mechanical property, this project studied the reinforcement of ATZ (alumina toughened zirconia) with oriented carbon nanofibers (CNFs) achieving orientation through the printing method of direct ink writing (DIW). The ATZ composite was reinforced by CNFs in contents of 0.5 and 2.0 wt%, whereas sintering was performed by the Spark Plasma Sintering (SPS) method. The optimized deflocculant content was shown to be 1.0 wt%, a value that was utilized for all the suspensions produced. The maximum solid content of the suspension was determined to be 47 vol%. The rheological evaluations showed that the addition of the highest CNF content (2.0 wt%) resulted in the displacement in the suspension behavior equivalent to a 3 vol% increment in solid content. A study of the microstructural features of the printed components was conducted, including the characterization of the defects, the orientation of the fibers and the mechanical behavior.