Angiogenesis serves a role in the growth, metastasis and prognosis of tumors. The aim of the present study was to evaluate the angiogenic ability and clinical significance of the immune biomarker soluble interleukin‑2 receptor (sIL‑2R) in gastric cancer (GC) patients. Serum levels of sIL‑2R were measured in 35 GC patients with different stages of disease and 32 healthy individuals, and it was investigated whether the levels were associated with angiogenesis factors, including vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)‑β1. Human umbilical vein endothelial cells (HUVECs) were pretreated with or without recombinant human (rh)sIL‑2R, VEGF and TGF‑β1 for 24 h, and then the HUVECSs were harvested to determine the degree of angiogenesis. The supernatants were also collected for VEGF and TGF‑β1 testing. Serum levels of sIL‑2R were higher in GC patients than in healthy individuals, as were the levels of VEGF and TGF‑β1. In addition, serum levels of sIL‑2R were positively associated with the levels of VEGF and TGF‑β1. Angiogenesis of HUVECs was also increased by rhsIL‑2R pretreatment. VEGF and TGF‑β1 secretion were also incre-ased in supernatants that were pretreated with rhsIL‑2R. The results of the present study suggested that serum levels of sIL‑2R contributes to the pathophysiology of GC progression and may be used as a prognostic biomarker for GC.