The relative paucity of mesenteric fat seen in the pediatric population can make detection and localization of processes in the mesentery difficult. This pictorial essay reviews pediatric mesenteric disorders and presents criteria that help localize processes to the mesentery. Disorders are categorized by specific patterns of involvement, which can readily be identified by imaging: developmental abnormalities of mesenteric rotation, diffuse mesenteric processes, focal mesenteric masses, and multifocal mesenteric masses.