Aim: Gastric cancer patients are normally treated with oral fluoropyrimidine and cisplatin or oxaliplatin; however, treating patients who also have a gastrointestinal obstruction is often difficult because of their poor oral intake. Instead, a modified (m)FOLFOX‐6 regimen is administered, even to patients with gastrointestinal obstructions. The aim of this study was to assess the efficacy of mFOLFOX‐6 for gastric cancer patients with a gastrointestinal obstruction. Methods: Patients with a poor oral intake because of a gastrointestinal obstruction who received mFOLFOX‐6 as systemic chemotherapy were retrospectively analyzed. Poor oral intake was defined as receiving a daily intravenous drip infusion due to a gastrointestinal obstruction. Results: Eighteen patients received mFOLFOX‐6; the median progression‐free survival was 6.8 months (95% confidence interval [CI], 1.9–9.7), the median overall survival was 8.0 months (95% CI, 2.8–20.8) and the median time to treatment failure was 2.2 months (95% CI, 1.2–5.7). An improved oral intake was observed in 13 of the 18 treated patients, with 12 of these continuing treatment as outpatients. Conclusions: A mFOLFOX‐6 treatment regimen seems promising for gastric cancer patients who have a gastrointestinal obstruction. [ABSTRACT FROM AUTHOR]