Abstract-Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease in neonates, and effective strategies to prevent and treat NEC are still lacking. Studies have shown that N-acetylcysteine (NAC) has protective effects against NEC, however, the specific mechanism underlying its effects on intestinal functions remains unclear. Recently, NAC has been shown to suppress ferroptosis in many diseases, while it is unclear whether the beneficial effects of NAC on NEC are related to ferroptosis. In this study, we revealed that ferroptosis was significantly induced in intestinal samples from infants with NEC. NAC alleviated intestinal inflammation, barrier damage and ferroptosis in multifactorial NEC models in vivo and in vitro. Sestrin2 (SESN2) was identified as an important mediator of NAC-induced ferroptosis resistance in intestinal epithelial cells. Furthermore, SESN2 knockdown inhibited the inflammatory response, alleviated barrier damage and ferroptosis in intestinal epithelial cells and enhanced the protective effects of NAC to a certain extent. Conversely, cells overexpressing SESN2 showed the opposite changes. In summary, our study demonstrated that NAC attenuates NEC progression by decreasing SESN2 expression to inhibit ferroptosis in intestinal epithelial cells, suggesting that NAC might be an effective clinical treatment for NEC.