Phytochemicals were obtained from potato peel using conventional and subcritical water (sCW) extraction. The influence of process parameters on the removal of carbohydrates, phenolics and antioxidant compounds were optimized using Response Surface Factorial Design and the Taguchi method. Ethanol concentration (1–90%) and pH (3–10) were studied for the conventional extraction and static holding time (2–25min), pressure (40–120bar), temperature (140–260°C), and pH (3–9) were studied for the sCW extraction. Higher amounts of phytochemicals were obtained with the sCW extraction than with the conventional extraction. The highest total carbohydrates (610mg GEg −1 potato peel), total phenolics (20mgGAEg −1 potato peel), and total antioxidant activity (42mgFeSO 4 g −1 potato peel) with low browning color of the extracts were obtained at 40bar, 190°C, and 9min of static holding time using a flow rate of 3mLmin −1 . The proposed dynamic mass transfer-reaction model fitted well the experimental data with a mean square error of 0.4 and predicted well the potato peel residual mass.