The aquaporins (AQPs) are a family of 13 small hydrophobic integral transmembrane water channel proteins involved in transcellular and transepithelial water movement, transport of fluid and cell migration.This review article summarizes our knowledge concerning the involvement of AQPs in tumor growth, angiogenesis and metastatic process.Tumor cells types express AQPs and a positive correlation exists between histological tumor grade and the AQP expression. Moreover, AQPs are involved also in tumor edema formation and angiogenesis in several solid and hematological tumors.AQPs inhibition in endothelial and tumor cells might limit tumor growth and spread, suggesting a potential therapeutic use in the treatment of tumors. This article is part of a Special Issue entitled Aquaporins.