Abstract INTRODUCTION Radiotherapy has been a cornerstone in pediatric oncology for decades. Recognizing the potential to mitigate side effects, proton therapy (PT) has gained prominence, becoming part of treatment in pediatric oncology in Slovakia since 2014. METHODOLOGY This retrospective analysis investigates a cohort of patients with CNS tumors treated at the National Institute of Children’s Diseases in Bratislava, who underwent PT at the Proton Center in Prague between 2014 and 2022. RESULTS Among 47 patients, embryonal tumors constituted the largest group (40%), followed by germ cell tumors (21%), ependymal tumors (19%), less common CNS tumors (10%), and glial tumors (8%). Acute complications included skin toxicity (38%), CNS toxicity (23%), GIT toxicity (14%), and blood count changes (8%). Notably, 22 patients experienced no acute toxicity. Late reactions, predominantly endocrine dysfunction (65%), featured central hypothyroidism (45%), ACTH deficiency (22%), GH deficiency (16%), and gonadotropin deficiency (10%). Ocular complications affected 55%, while tensive cephalea and post-radiation necrosis-related epileptic seizures were observed in limited cases. Disease recurrence was absent in 89% of patients, with 10% exiting due to disease progression. CONCLUSION This pioneering analysis highlights the unique experiences of Slovak pediatric patients undergoing PT at the Proton Center in Prague. The study emphasizes the dual impact of PT, enhancing survival rates while reducing adverse effects, thereby significantly contributing to a better quality of life for pediatric cancer patients.