To assess the analgesic efficacy and side effects of a supplemental night-time infusion in patient-controlled epidural analgesia (PCEA) after gastrectomy, we carried out a randomized, double-blind study. The number of requests were lower (P <0.005) in the PCEA plus night-time infusion group than in the PCEA alone group during the postoperative nights. Patients who had a PCEA plus night-time continuous infusion, slept with fewer interruptions than those who had only the PCEA. VAS pain scores on coughing were significantly lower (P <0.05) in the PCEA plus infusion group than in the PCEA alone group during the night following postoperative day 1. In conclusion, a night-time infusion in PCEA following gastrectomy decreases the incidence of postoperative pain, provides a better sleep pattern, and reduces the degree of the pain associated with coughing during the night.