The loss of a lower limb can have a profound impact on an individual's mobility and independence. To address this issue, transtibial prosthetic sockets (TPS) have been developed as medical devices to assist amputees in regaining their mobility. However, the production of these TPS has encountered challenges due to the diverse range of process variables (PV) involved. This study aimed to examine the flexural behavior of poly lactic acid reinforced with carbon fiber (PLA-CF) using the fused filament fabrication (FFF) technique. The specific objectives were to investigate the influence of two PV: the nozzle hole diameter (NHD) with options of 0.15, 0.25, and 0.40 mm, and the internal filling pattern (IFP) with options of grid, honeycomb (HC), and tri-hexagon (TRH). To comprehend the impact of these PV on the flexural behavior, comprehensive flexural tests were conducted on the fabricated samples. Furthermore, the failure morphology of the samples was analyzed to gain insights into their structural integrity. The obtained data from the flexural tests were subjected to statistical analysis using the analysis of variance (ANOVA) by Taguchi methodology (TM). This statistical approach facilitated the determination of the relationship between the flexural behavior and the selected PV. The research findings have significant implications in the field of TPS development. By gaining an understanding of how different PV affect flexural behavior, it becomes possible to optimize the manufacturing process and enhance the performance of TPS.