Objective To investigate the changes and clinical significance of serum pro-gastrin-releasing peptide (ProGRP), squamous cell carcinoma-related antigen (SCC), and carbohydrate antigen 72-4 (CA72-4) levels in patients with gastric cancer. Methods A total of 68 patients with gastric cancer (gastric cancer group), 37 patients with benign gastric lesions (benign gastric lesion group), and 30 healthy subjects (non-gastric disease group) were selected as the study participants. Serum ProGRP, SCC, and CA72-4 levels were compared among the three groups on admission. The relationships of serum ProGRP, SCC, and CA72-4 levels with pathological parameters were analyzed in the gastric cancer group. Patients in the gastric cancer group were followed up for 24-month after discharge. Multivariate Logistic regression analysis was used to identify the influencing factors of prognosis in gastric cancer patients. Receiver operating characteristic (ROC) curves were plotted and the area under the curve (AUC) was calculated to analyze the predictive value of serum ProGRP, SCC, and CA72-4 for death during follow-up in gastric cancer patients. Results The serum levels of ProGRP, SCC, and CA72-4 in the gastric cancer group were higher than those in the benign gastric lesion group and the non-gastric disease group, and the serum levels of ProGRP and CA72-4 in the benign gastric lesion group were higher than those in the non-gastric disease group (P < 0.05). In the gastric cancer group, patients with TNM stage Ⅲ to Ⅳ, moderately-lowly differentiated histological grade, and lymph node metastasis had higher serum levels of ProGRP and CA72-4 than those with stage Ⅰto Ⅱ, high differentiation, and no lymph node metastasis. Patients with moderately-lowly differentiated histological grade had higher serum levels of SCC than those with high differentiated histological grade (P < 0.05). After 24 months of follow-up, 49 patients survived (survival group) and 19 patients died (death group) in the gastric cancer group. The serum levels of ProGRP, SCC, and CA72-4 in the death group were higher than those in the survival group on admission (P < 0.05). Multivariate Logistic regression analysis showed that serum ProGRP, SCC, and CA72-4 were independent influencing factors for the prognosis of gastric cancer patients (P < 0.05). Serum ProGRP, SCC, and CA72-4 had good predictive efficacy for death during follow-up in gastric cancer patients (AUC=0.766, 0.705, 0.828), and their combined predictive efficacy was better (AUC=0.899). Conclusion The serum levels of ProGRP, SCC, and CA72-4 that are related to TNM stage, histological grade, and lymph node metastasis in patients with gastric cancer are abnormally elevated, and their combined detection has good predictive efficacy for death during follow-up.