In recent years, metronomic chemotherapy, consisting of continuous administration of low doses of cytotoxic agents, has being used as rescue therapy for different tumours. The aim of this study was to retrospectively assess the efficacy and safety of low-dose metronomic, oral capecitabine in pretreated or frail patients with recurrent upper gastrointestinal tract cancer. Patients with pretreated upper gastrointestinal tract cancer or who were not candidates for standard chemotherapy because of toxicity concerns received capecitabine at 1500 mg per day continuously until disease progression or occurrence of toxicity. Forty-seven patients (25 oesophagogastric cancer, 22 pancreatobiliary cancer; 25 men, 22 women; median age 69 years, range 42-90) were included in the study. Forty-five percent of the patients had received at least two previous lines of treatment and the median number of previous treatments was 1 (range 0-5). Twelve (31.6%) patients achieved clinical benefit (one partial response, 11 stable disease), whereas nine (23.7%) patients were progression free for at least 6 months. In an exploratory analysis, there was a significant relationship between performance status and clinical benefit (hazard ratio=8.25; P=0.01). The median overall survival was 5 months. A good performance status was associated with a longer survival (hazard ratio=0.26; P<0.01). No severe toxicity or treatment-related death was reported. Metronomic capecitabine showed good safety and moderate activity in frail or pretreated patients with advanced, upper gastrointestinal tract cancer.