Pediatric central nervous system (CNS) tumors, including gliomas, medulloblastomas, and diffuse midline gliomas (previously diffuse intrinsic pontine gliomas), remain a major clinical challenge due to their complex biology, limited treatment effectiveness, and generally poor prognosis. Standard treatments are often aggressive and associated with substantial toxicity, particularly in advanced stages. This review highlights recent developments in radiopharmaceuticals for molecular imaging and targeted radiotherapy. A comprehensive literature analysis was conducted, focusing on radiotracers with clinical relevance in pediatric neuro-oncology, including metabolic, peptide receptor-based, and antibody-based agents. Radiopharmaceuticals such as 18F-FLT, 64CuCl2, and 1-L-18F-FETrp have improved the ability to monitor tumor biology, proliferation, and treatment response, aiding in diagnosis at an early stage, assessment of tumor behavior, and detection of recurrence or progression. Additionally, peptide receptor-based radiotracers, such as 68Ga-DOTATATE and 177Lu-DOTATATE, are already used for both diagnostic purposes and targeted radiotherapy, particularly in neuroblastomas and gliomas. Antibody-based radiotracers like 131I-omburtamab, targeting B7-H3, are emerging as promising tools for addressing difficult-to-treat tumors such as diffuse midline glioma. Collectively, these advances provide new hope for children afflicted by these devastating malignancies, offering promising solutions for more specific and precise diagnosis and, additionally, for more effective, personalized, and less toxic tumor therapies.