Gastric cancer is one of the most frequent malignant tumours worldwide and it is linked to a high mortality. Henceforth, it is necessary to determine the factors contributing to its occurrence, the adequate diagnostic methods and the most effective treatment. Currently, surgery is the only form of therapy providing the possibility of fully curing patients with gastric cancer. This paper includes an analysis of patients with gastric cancer surgically treated in a five-year period (2016 - 2020) at University Hospital Centre Zagreb. The goal of this analysis was to determine the efficacy of various types of lymphadenectomy as a part of surgical gastric cancer treatment and their effect on the patients’ survival. In total, 135 patients were treated using surgical procedures with curative intent, 73 of which were treated with D2 lymphadenectomy. The 1-year, 3-year and 5-year survival rates of patients treated with D2 lymphadenectomy were 61%, 39% and 29%, respectively. These survival rates were somewhat lower than in patients treated with less extensive lymphadenectomies (68%, 44% and 38%, respectively). Using comparative analysis of the lymphadenectomy type and the cancer stage, it was found that D2 lymphadenectomies were more frequently applied in patients with higher cancer stages. In conclusion, the performed analysis did not prove that a D2 lymphadenectomy has an effect on the long-term survival of patients compared to the less extensive lymphadenectomies. The probable cause of the lower survival rate of the patients treated with D2 lymphadenectomies is the fact that this method was mostly applied in patients with higher cancer stages which have a poorer prognosis irrespectively of the treatment. The overall survival rates of patients are also low, mostly due to late diagnoses when the chances of curing the patients are significantly lower.