Background and Aims Necrotizing enterocolitis (NEC) which is accompanied with gastrointestinal ulceration and necrosis is one of the most important problems of preterm infants in neonatal intensive care unit (NICU). Increased intra-abdominal pressure (IAP) is detected among most of the pediatric patients hospitalized in intensive care unit and undergoing surgery or trauma. This pathology, namely, abdominal compartment syndrome, causes ischemia and hypoperfusion of abdominal organs. Recently, the effect of increased IAP on NEC is under focus and this increase is thought to be related with the onset of NEC by leading to intestinal ischemia and necrosis. In this study, we aimed to investigate if serial intravesical pressure (IVP) measurements as an indirect indicator of IAP may help to early diagnosis in NEC and to decision for surgery besides to predict the mortality of NEC.