ATP-binding cassette C4/multidrug resistance associated protein 4 (ABCC4/MRP4) is a relatively well-studied member of the ATP-binding cassette drug transporter family. Recent studies suggested that ABCC4 is implicated in the development of several human cancers. In the present study, we report that knockdown of ABCC4 by lentivirus-delivered short hairpin RNA could inhibit gastric cancer cell growth in vitro. The proliferation of MGC80-3 cells was significantly reduced after infection with Lv-shABCC4, as determined by MTT and colony formation assays. In addition, knockdown of ABCC4 blocked the cell cycle progression in MGC80-3 cells. To our knowledge, it is the first report to investigate the role of ABCC4 in gastric tumorigenesis. Our data provides additional evidence that ABCC4/MRP4 could be a potential therapeutic target for gastric cancers.