Abstract: The impact of IVIg on metastatic capacity of CT26 murine colon carcinoma cells was studied using in vitro and in vivo methods. IVIg inhibited CT26 cell proliferation and invasion through an extracellular matrix in a dose- and time-dependent manner. Systemic treatment of mice with IVIg significantly inhibited metastatic potential of CT26 colon carcinoma cells observed as tumor nodules and lung weight reduction. Treating CT26 cell-implanted rabbit corneas with IVIg led to shrinking and complete disappearance of tumor mass in 10 days. These results provide the evidence that IVIg may be considered as a supportive therapy for inhibition of colon carcinoma tumor spread.