Dipeptidyl peptidase IV (DPPIV) is a multifunctional cell surface aminopeptidase with ubiquitous expression. Recent studies have suggested that DPPIV plays an important role in tumor progression in several human malignancies. In the present study, we investigated the correlation between DPPIV expression and progressive potential in ovarian carcinoma. We demonstrated that ovarian carcinoma cell lines with higher DPPIV expression were less invasive. Furthermore, DPPIV overexpression in SKOV3 cells, derived from serous cystadenocarcinoma, with little DPPIV expression induced a dramatic change in cellular morphology and a significant decrease in the abilities of both migration and invasion. In addition, we have also shown that nude mice inoculated with DPPIV-transfected SKOV3 cells showed significantly less peritoneal dissemination and longer survival time than those receiving the parental or vector-only transfected cells (mean survival time, 64.9 +/- 4.7, 35.7 +/- 2.8, and 36.6 +/- 1.8 days, respectively). This evidence implies that DPPIV may functionally suppress peritoneal dissemination in ovarian carcinoma.