This is a whole population-based study on clinical symptoms, surgical treatment, and outcome of GIST. All mesenchymal tumors in the digestive tract diagnosed from 1990 to 2003 were identified. All reports were reviewed, all tumors were stained with antibodies to c-kit, and the diagnosis of GIST was confirmed. Clinical, pathological, treatment, and outcome data were analyzed. The study included 53 patients with GIST. The mean age at diagnosis was 65.8+/-13.6 years (SD). Tumor distribution included 62% in the upper, 32% in the middle, and 6% in the lower digestive tract. Mean tumor size was 4.9+/-4.4 cm (SD). Gastrointestinal (GI) bleeding was the main symptom in 53% (20/38) of symptomatic cases; most presented with acute gastrointestinal bleeding. Complete surgical resection was performed in 87% (46/53) of patients. Eight of the 53 tumors (15.1%) metastasized, 7 of which were nongastric. The disease-specific death rate at 5 years was 85%, and 5-year survival after complete resection was 64.1%. We conclude that GISTs are often found incidentally but GI bleeding is the most common presentation. Five-year survival is better than previously reported and gastric GIST seems to be more benign than nongastric. GIST seems to metastasize mainly intra-abdominally.