BACKGROUND: Epidural analgesia (EDA) is a main modality for postoperative pain relief in major open abdominal surgery within the Enhanced Recovery After Surgery protocol. However, it remains unclear whether EDA is an imperative modality in laparoscopic gastrectomy (LG). This study examined non-inferiority of patient-controlled intravenous analgesia (PCIA) to EDA in terms of postoperative pain and recovery in patients who underwent LG. METHODS: In this open-label, non-inferiority, parallel, individually randomized clinical trial, patients who underwent elective LG for gastric cancer were randomized 1:1 to receive either EDA or PCIA after surgery. The primary endpoint was pain score using the Numerical Rating Scale at rest 24 h after surgery, analysed both according to the intention-to-treat (ITT) principle and per protocol. The non-inferiority margin for pain score was set at 1. Secondary outcomes were postoperative parameters related to recovery and adverse events related to analgesia. RESULTS: Between 3 July 2017 and 29 September 2020, 132 patients were randomized to receive either EDA (n = 66) or PCIA (n = 66). After exclusions, 64 patients were included in the EDA group and 65 patients in the PCIA group for the ITT analysis. Pain score at rest 24 h after surgery was 1.94 (s.d. 2.07) in the EDA group and 2.63 (s.d. 1.76) in the PCIA group (P = 0.043). PCIA was not non-inferior to EDA for the primary endpoint (difference 0.69, one side 95% c.i. 1.25, P = 0.184) in ITT analysis. Postoperative parameters related to recovery were similar between groups. More EDA patients (21 (32.8%) versus 1 (1.5%), P < 0.001) developed postoperative hypotension as an adverse event. CONCLUSIONS: PCIA was not non-inferior to EDA in terms of early-phase pain relief after LG.Registration number: UMIN000027643 (https://www.umin.ac.jp/ctr/index-j.htm).