Extravasation of cytostatic drugs is a rare but potentially devastating complication of chemotherapy in children, leading to severe pain, tissue necrosis, functional impairment, and cosmetic deformities. Despite its importance, management protocols remain inconsistent. This paper presents structured instructions to support rapid recognition, intervention, and prevention of cytostatic extravasation in paediatric patients, aiming to reduce morbidity and optimise outcomes. The guidance was developed from published recommendations, systematic reviews, and institutional experience, and it provides a stepwise algorithm for immediate management: stopping infusion, retaining intravenous access for aspiration, marking and documenting the affected site, and performing clinical assessment. Specific measures include aspiration techniques for peripheral and central lines, administration of antidotes such as dexrazoxane, dimethyl sulfoxide, or hyaluronidase, and application of cold or warm compresses depending on the cytostatic agent. Preventive strategies emphasise correct vessel selection, careful cannula monitoring, and strict adherence to administration procedures. For advanced necrosis or refractory injury, surgical approaches – such as early wash-out, liposuction, excision with negative- pressure wound therapy, skin grafting, and complex reconstructions – are outlined. The proposed framework integrates available evidence and expert consensus into a practical and user-friendly protocol. Its implementation may facilitate early detection, minimise the risk of severe complications, and promote standardised paediatric oncology care. In conclusion, cytostatic extravasation in children requires prompt, structured, interdisciplinary management. Early use of specific antidotes and supportive measures can prevent irreversible damage, while preventive strategies and vigilant monitoring remain crucial. Surgical interventions should be reserved for severe, non-responsive cases.