A retrospective study of 954 resectable gastric cancers in a single institute of Taiwan from 1971 to 1990 was performed to evaluate improvements in gastric cancer surgery. The patients were divided into four time periods representing an overall experience of progressive implementation of aggressive resection and increased extent of systematic lymph node dissection. The clinicopathologic data and survival rates were statistically compared and the significance of the extent of resection on survival analyzed. A significant increase in the proportion of upper one-third tumors (from 14.8% to 20.4%) and a decrease in the incidence of intestinal type (73.6% to 41.5%) was found within the overall period. The proportion of patients with early gastric cancer increased from 11.5% to 19.4%. Patients who underwent total gastrectomy and combined visceral resection increased from 13.7% to 27.4% and 19.8% to 41.1%, respectively. An increase of both total dissected lymph node number and the incidence of detected lymph node metastases in early gastric cancer were associated with more extensive lymphadenectomy. An improved 5-year survival rate following aggressive resection was found for all stages except stage IV and T4 lesions, and the surgical mortality decreased from 5.5% to 2.0%. Patients with earlier stage lesions benefited more from radical resection, especially those with stage II and T2 lesions. Systematic lymph node dissection increased the 5-year survival of patients by about 10% for stage III or T3 lesions but not for patients with stage IV or T4 lesions. Multivariate analysis confirmed the significance of the improved technique of lymphadenectomy on the prognosis of gastric cancer following resection in Taiwan.(ABSTRACT TRUNCATED AT 250 WORDS)