Emerging evidence has supported the idea that goal-directed prehabilitation is a promising approach to boost functional capacity in preoperative patients. However, its usefulness has not been tested in the hepatobiliary and pancreatic (HBP) field. The objective of this trial was to investigate the efficacy of goal-directed prehabilitation for improving functional capacity in patients who were planned to undergo major HBP operations. This assessor-blinded, parallel-arm, randomized clinical trial recruited patients who were scheduled for major HBP surgeries for malignancy. Patients were randomly allocated into the step goal-directed prehabilitation (GOLD) group as the test group and into the conventional prehabilitation (CONV) group as the control group. Patients in the GOLD group participated in a walking prehabilitation program with an intergrading goal of the step count. Patients in the CONV group received standard physical and nutritional prehabilitation. The primary outcome was change in the 6-minute walking distance (6MWD), which ranged from the time before starting prehabilitation (baseline) to the time after completing prehabilitation (immediately before surgery). Among 180 randomized patients, 144 patients were included in the primary analysis (73 patients in the CONV group and 71 patients in the GOLD group). The mean change in the 6MWD was 27 m in the CONV group and 31 m in the GOLD group (P = 0.633). In patients undergoing major HBP surgeries for malignancies, a goal-directed prehabilitation program did not result in a significantly greater increase in functional capacity than did conventional prehabilitation. Registration number: UMIN000038791 (https://www.umin.ac.jp/). Display omitted