Textbook outcome (TO) is widely recognized as a comprehensive prognostic indication for patients with gastric cancer (GC). This study aims to develop a modified TO (mTO) for elderly patients with GC. Data from the elderly patients (aged ≥ 65years) in two Chinese tertiary referral hospitals were analyzed. 1389 patients from Fujian Medical University Union Hospital were assigned as the training cohort and 185 patients from Affiliated Hospital of Putian University as the validation cohort. Nomogram was developed by the independent prognostic factors of Overall Survival (OS) based on Cox regression. In the training cohort, laparoscopic surgery was significantly correlated with higher TO rate (P < 0.05). Cox regression analysis revealed that surgical approach was also an independent factor of OS (P < 0.001), distinct from the traditional TO. In light of these findings, TO parameters were enhanced by the inclusion of surgical approach, rendering a modified TO (mTO). Further analysis showed that mTO, tumor size, pTNM staging, and adjuvant chemotherapy were independent prognostic factors associated with OS (all P < 0.05). Additionally, the nomogram incorporating these four indicators accurately predicted 1-, 3-, and 5-year OS in the training cohort, with AUC values of 0.793, 0.814, and 0.807, respectively, and exhibited outstanding predictive performance within the validation cohort. mTO holds a robust association with the prognosis of elderly patients with GC, meriting intensified attention in efforts aimed at enhancing surgical quality. Furthermore, the predictive model incorporating mTO demonstrates excellent predictive performance for elderly patients with GC.