Permanent synovial sarcoma cell lines are invaluable tools for understanding of the biology of this tumor. The present study reports the establishment of a new human cell line, PDSS-26, derived from a surgical specimen of a poorly differentiated synovial sarcoma. PDSS-26 has a doubling time of a 72 hours and grows as a monolayer of spindle cells that retain immunoreactivity for bcl-2 and vimentin. Karyotypic analysis revealed a rearrangement involving chromosomes 17 and 18, at the breakpoints q11.2 and q11.2, respectively, as the only structural aberrations. Analysis by reverse transcriptase polymerase chain reaction showed the presence of the SYT-SSX1 fusion transcript in both the primary tumor and the cell line. Cytoplasmic PTEN staining was detected by immunohistochemistry in both the PDSS-26 cell line and in original tumor, whereas no mutation was identified by automatic sequencing. Thus, PDSS-26 cells could be useful for future functional studies.