The present study was undertaken to investigate the biological activity of serum albumin when pancreatic β cells were challenged by cytokines and pro-apoptotic reactive oxygen species like H₂O₂. Culture of mouse islets or INS-1E β cells for 24 h in the presence of H₂O₂ (25 μmol/l) increased cell death. This demise was prevented by serum albumin, dependent on its free sulfhydryl group, emphasizing that albumin may scavenge H₂O₂ due to its antioxidant properties. Culture for 48 h with a cytokine mixture of IL-1β (160 pg/ml), IFN-γ (200 ng/ml), and TNF-α (2 ng/ml) revealed that albumin, also protected against cytokine-induced death of both mouse islets and INS-1E β cells. This protective effect against cytokine-induced β cell death was, however, not dependent on albumins free sulfhydryl group, but was inhibited by the phosphoinositide 3-kinase (PI3K) inhibitors LY294002 (25 μmol/l) and wortmannin (1 μmol/l), suggesting that albumin may rescue β cells from cytokine-induced cell death by activation of PI3K. In accordance, albumin stimulated phosphorylation of Akt, a down-stream target for PI3K. In conclusion, it is suggested that albumin may be a survival factor for pancreatic β cells through scavenging of reactive oxygen species and by PI3K-dependent activation of Akt.