Syndecan-1 is a transmembrane heparan sulfate proteoglycan which plays pivotal role in cell-cell and cell-extracellular matrix interactions. However, its implication in the establishment of malignant phenotype is still controversial. Its expression indicates differentiated phenotype in certain tumors, while it confers invasive nature for others. For the better understanding of the role of syndecan-1 in cancer we transfected HT-1080 fibrosarcoma cell line with the full and a truncated construct of syndecan-1 and established stable cell lines with them. We studied the in vitro and in vivo growth capacity and metastatic potential of the transfectants in comparison with the cell line bearing only the EGFP expression vector. Our results showed that the growth rate of syndecan transfectants increased and they developed more lung metastases than the control cells. As local growth of the full transfectant was faster than that of the 78sig we presume that the full protein and maybe the shedding is needed for the local development of the tumor, but the intracellular and transmembrane domain is sufficient to promote metastasis formation.