The last few years have seen the identification of pharmacologic approaches to target bromodomain and extraterminal (BET) proteins for cancer treatment. These proteins have an essential role in gene transcription regulation by binding acetylated lysine residues on histone tails, activating gene transcription. BET inhibitors have been tested in preclinical models including pediatric malignancies and several adult clinical trials are ongoing. Since the development of new drugs in pediatric cancer has long lagged behind programs for adults, the aim of this review is to show the importance of these therapies in pediatric malignancies to support their development in pediatric oncology/hematology.