Radionuclide techniques are currently used to fully evaluate many congenital and acquired abnormalities of the gastrointestinal tract of children. Frequently, the anatomic and functional data provided by the nuclear examination are definitive. In the study of many disease entities, tracer techniques have replaced more cumbersome or invasive procedures. Although the radiopharmaceuticals and instrumentation are similar as applied to both children and adults, the uniqueness of children and their disease entities requires special consideration when performing and interpreting their studies. In this review, the principle radionuclide examinations used in the evaluation of pediatric gastrointestinal disorders are detailed and examples are illustrated.