The major determinants of the poor prognosis of the patients with proximal-third gastric cancer (proximal gastric cancer or PGC) when compared with that of patients with more distally located gastric tumors (distal gastric cancer or DGC) rely both on the more advanced age and tumor stage at the moment of clinical presentation and on the higher postoperative mortality for PGC patients. We reviewed hospital records of 707 patients with gastric cancer (187 with PGC and 520 with DGC) observed during the period 1981 through 1996 at the same surgical unit. Demographic and pathological data, type of treatment, and hospital morbidity and mortality rates were recorded. Univariate and multivariate survival analysis was used to calculate the 5-year survival probabilities with respect to the following clinical and pathological variables: age, sex, gross appearance according to Borrmann classification, histological type according to Lauren, stage of the disease, tumor location, and type of treatment. PGC was associated with more advanced tumor stage (P < 0.0001), older age (P = 0.039), and higher necessity of extended surgery (P < 0.0001) when compared with DGC. Hospital mortality was 9.6 and 5 per cent in PGC and DGC patients respectively (P = 0.033). Overall 5-year survival was 17.7 and 36.4 per cent in PGC and DGC patients (P < 0.0001): 35.9 versus 57.6% (P = 0.0001) and 3.7 versus 7.6 per cent (P = 0.03) after radical and palliative surgery respectively. At multivariate survival analysis proximal location was found to be independently associated (P = 0.0007) with poor survival. The multivariate model shows the proximal location as an independent predictor of lesser favorable outcome in gastric cancer. The major determinants of the poor prognosis of PGC with respect to DGC rely both on the more advanced age and tumor stage at the moment of clinical presentation and on the higher postoperative morbidity for PGC patients.