Approximately 40-50% of children with cancer will be irradiated during their treatment. Intensity-modulated radiotherapy (IMRT) by linear accelerator or helical tomotherapy improves dose distribution in target volumes and normal tissue sparing. This technology could be particularly useful for pediatric patients to achieve an optimal dose distribution in complex volumes close to critical structures. The use of IMRT can increase the volume of tissue receiving low-dose radiation, and consequently carcinogenicity in childhood population with a good overall survival and long period of life expectancy. This review will present the current and potential IMRT indications for cancers in childhood, and discuss the benefits and problems of this technology aiming to define recommendations in the use of IMRT and specific doses constraints in pediatry.