Objective: Surgery followed by chemotherapy with or without radiotherapy and perioperative chemotherapy represents the standard treatment modality in locally advanced gastric cancer patients. Adjuvant radiotherapy has been shown to have no benefits in these patients, especially those undergoing D2 dissection without neoadjuvant treatment. The goal of our study was to identify the prognostic factors associated with adjuvant treatments, particularly radiotherapy. Material and Methods: We evaluated the clinical, laboratory, and histological features and survival in locally advanced gastric cancer patients who underwent upfront gastric resection without neoadjuvant therapy and were subsequently treated with adjuvant chemotherapy comprising capecitabine-oxaliplatin. Parameters with significant p-values in univariate analysis were included in multivariate Cox regression analysis. Results: A total of 56 patients were included, and the median followup period was 33.2 months. The mean age was 61.23±8.89 years. The median disease-free survival (DFS) was 37.80 months (95% confidence interval: 22.30-53.30). The 5-year DFS and overall survival (OS) rates were 43.4% and 60.8%, respectively. In univariate analysis, lymph node involvement, diffuse histology, presence of lymphovascular invasion, positive surgical margin, presence of perineural invasion, absence of radiotherapy, and high lactate dehydrogenase (LDH) levels were found to be associated with shorter DFS and OS. In multivariate Cox regression analysis, diffuse histology, absence of radiotherapy, and high LDH levels were found to be associated with shorter DFS and OS. Conclusion: The long-term survival rates in our study were encouraging. Inflammatory markers, tumor histology, and radiotherapy might have prognostic value in identifying high-risk patients who could benefit from intensive therapy.