Objectives: Necrotizing enterocolitis (NEC) is a common cause of morbidity in the neonatal care units, especially in cases of preterm neonates with low and very low birth weight. Plain abdominal radiography remains to be the main diagnostic tool in the diagnosis and follow-up of NEC. However, it is sometimes impossible to depict all pathological findings in the radiographs. Furthermore, radiography exposes the youngest, most sensitive patients to consecutive episodes of radiation. Ultrasound examination seems to be an interesting alternative to current standard usage of radiography, and its role is still underestimated. The aim of the paper was to assess the applicability of ultrasound examination in the diagnosis and monitoring of neonates suffering from NEC. Material and methods: The study group consisted of 12 neonates (gestational age 25-36 weeks, weight 540-1900 g), suspected of NEC development. Abdominal radiographs obtained with the use of anterior-posterior and lateral projections, as well as ultrasound examination, were performed. During bowel sonography, attention was paid to the presence of intraabdominal fluid, free intraperitoneal gas, bowel wall thickness and bowel wall perfusion. Intramural gas, free intraperitoneal gas and signs of bowel distension were evaluated on the radiographs. Results: Bowel distension was found in all patients. The presence of intraluminal gas was detected in 3 neonates, whereas the signs of bowel perforation were present in only 2 patients. Ultrasound evaluation revealed bowel wall thickening together with increased bowel wall perfusion in 9 patients. Only one neonate presented thinning of the bowel wall, decreased bowel wall perfusion and presence of free intraperitoneal fluid. These findings were connected with a poor outcome of that patient. Conclusions: Ultrasound examination can be extremely helpful for the initial diagnosis as well as the follow-up of patients developing NEC. It allows to depict the majority of pathological findings for NEC, even those not visible on plain abdominal radiography. It is important to emphasize that abdominal sonography (with special reference to the bowel sonography), together with plain abdominal radiography, should be considered as standard imaging modalities for the assessment of necrotizing enterocolitis.