This study investigates the application of the Taguchi method and Response Surface Methodology (RSM) for optimizing process parameters in Abrasive Water Suspension Jet (AWSJ) machining of carbon fiber-reinforced polymer (CFRP) composite-based orthopedic implants. The research focuses on the effects of key process parameters such as abrasive size, standoff distance (SOD), abrasive concentration, and feed rate on material removal rate (MRR), kerf width, and surface roughness (SR) under both free air and underwater cutting conditions. The study demonstrates that underwater cutting consistently outperforms free air cutting in terms of MRR, kerf width, and SR. For instance, at an abrasive size of #100 and SOD of 5 mm, the MRR reached 2.44 g/min with a kerf width of 0.89 mm and SR of 9.25 μm. Increasing abrasive size and SOD further enhanced MRR, with values of 2.15 g/min at #120 grit and 3 mm SOD. The Taguchi method and RSM were employed to optimize machining parameters, leading to improved MRR and surface quality. The Taguchi method identified SOD as the most significant factor affecting MRR, while RSM provided a mathematical model to predict MRR based on process parameters. The results showed that increasing abrasive size, SOD, and abrasive concentration significantly improved MRR, while reducing feed rate had a negative impact. The study also highlights the effectiveness of underwater cutting in achieving higher MRR and better surface quality compared to free air cutting. The findings contribute to the optimization of AWSJ machining processes for CFRP composite-based orthopedic implants, offering valuable insights for improving machining efficiency and quality. The study emphasizes the importance of statistical methods in optimizing process parameters and enhancing the performance of AWSJ machining in composite materials.This study investigates the application of the Taguchi method and Response Surface Methodology (RSM) for optimizing process parameters in Abrasive Water Suspension Jet (AWSJ) machining of carbon fiber-reinforced polymer (CFRP) composite-based orthopedic implants. The research focuses on the effects of key process parameters such as abrasive size, standoff distance (SOD), abrasive concentration, and feed rate on material removal rate (MRR), kerf width, and surface roughness (SR) under both free air and underwater cutting conditions. The study demonstrates that underwater cutting consistently outperforms free air cutting in terms of MRR, kerf width, and SR. For instance, at an abrasive size of #100 and SOD of 5 mm, the MRR reached 2.44 g/min with a kerf width of 0.89 mm and SR of 9.25 μm. Increasing abrasive size and SOD further enhanced MRR, with values of 2.15 g/min at #120 grit and 3 mm SOD. The Taguchi method and RSM were employed to optimize machining parameters, leading to improved MRR and surface quality. The Taguchi method identified SOD as the most significant factor affecting MRR, while RSM provided a mathematical model to predict MRR based on process parameters. The results showed that increasing abrasive size, SOD, and abrasive concentration significantly improved MRR, while reducing feed rate had a negative impact. The study also highlights the effectiveness of underwater cutting in achieving higher MRR and better surface quality compared to free air cutting. The findings contribute to the optimization of AWSJ machining processes for CFRP composite-based orthopedic implants, offering valuable insights for improving machining efficiency and quality. The study emphasizes the importance of statistical methods in optimizing process parameters and enhancing the performance of AWSJ machining in composite materials.