Preclinical data strongly suggest that bevacizumab might be a very effective agent for the treatment of malignant ascites, which is in large part caused by the hyperpermeability-promoting factor VEGF. Emerging clinical results from cancer patients with malignant ascites treated with bevacizumab add further support to this idea. Bevacizumab has been tested in a variety of large clinical trials, has a good toxicity profile, and is effective in a number of human cancers underlying malignant ascites.