Background: The aim of this study was to evaluate the prevalence of enlarged mesenteric lymph nodes seen on pediatric abdominal ultrasound examinations performed in children with abdominal pain. Material/Methods: Ultrasound was performed with Sonoline Elegra and Philips iU-22 units with convex-array 2-5 MHz transducer for the general abdominal examination, and in addition with convex 5-8 MHz or linear 7.5 MHz transducers specially to detect lymph nodes. Results: Enlarged lymph nodes were found in 248 (21,2%) out of 1171 symptomatic patients. In 53 patients some other abnormalities were found. The nodes were mostly disc-like and oval in shape. They had usually a homogeneous appearance and were iso- or hypoechoic relative to the surrounding tissues and intestinal loops. Conclusions: Mesenteric lymphadenitis is commonly reported in children with acute, chronic or recurrent abdominal pain and no evidence of other pathologies, and has been reported as one of the most common explanation for acute right lower quadrant abdominal pain.