We conducted a randomized, multicenter, controlled trial of AO-90, a methionine-free 7.43% intravenous amino acid solution, in patients with advanced recurrent gastric cancer. The regimen used in the study was comprised of two-week treatment cycles, with a withdrawal period between cycles. During treatment, patients were given either AO-90 (500-750 ml/day; AO/MF group) or a commercial amino acid solution (600-800 ml/day; C/MF group) by total parenteral nutrition (TPN) for 14 days concomitantly with MF therapy (5-fluorouracil 350 mg/m2/day, iv continuously for 14 days and mitomycin C 7 mg/m2, iv push on days 7 and 14). We interviewed 118 eligible and evaluable patients (72 men and 46 women; 59 cases in the AO/MF group and 59 in the C/MF group) about their quality of life immediately before the start of treatment, one week and two weeks after the start of treatment, and one week and two weeks after treatment. A 11-item questionnaire was used to interview the subjects: nine questions using a five-point scale, one question using a 100-mm linear visual analog scale, and one question using a five-grade face scale. Changes in the grades compared with baseline data were scored as 1 point (improvement of one grade or more, or 20 mm or more), 0 points (no changes), and-1 point (decline of one grade or more, or 20 mm or more). Before analyzing the significance, quality of life score data were adjusted by the Mantel-Haenszel method due to uneven distribution of subjects concerning baseline performance status and complications. Among the items questioned, subjects receiving AO-90 showed significantly higher scores in appetite, nausea, and ambulation at some evaluation time points than those receiving a methionine-containing TPN. The results show that AO-90 improved the quality of life of patients with advanced recurrent gastric cancer.