Epileptic seizures are a common and clinically relevant problem in paediatric oncology. Attributable to the heterogeneity of this group of patients and a number of possible comorbidities antiepileptic treatment in paediatric oncology poses a number of diagnostic and therapeutic challenges. This requires a close interdisciplinary approach to the seizing child or adolescent. A prompt and detailed diagnostic work-up is needed in every case in order to establish the diagnosis and, equally important, to detect secondary aetiological factors, e. g. epileptogenic drugs or any acute underlying pathology, such as metabolic or toxic encephalopathies, CNS-infections or cerebrovascular events. This might offer the opportunity for a specific causative treatment and thus prevent unnecessary long-term antiepileptic drug (AED) treatment. If AED treatment is initiated several aspects have to be taken into account. Most importantly, AEDs and chemotherapeutic drugs (CTDs) may interact. Depending on the comedication this may result in reduced tumour or seizure control or unexpected toxicity of AEDs or CTDs. Understanding these interactions will allow to anticipate clinically relevant adverse effects. AED may be further complicated by side-effects, some of them of particular concern for children or adolescents, such as cognitive effects, myelotoxicity, serious rashes, endocrinological disturbances, and many more. Beside critically questioning the need for AED treatment it is therefore important to prefer AED with a good safety-profile in this population. Enzyme-inducing and inhibiting AED should be avoided if possible. Preliminary studies indicate that gabapentin and levetiracetam may provide good options in terms of efficacy and safety. However, more properly designed clinical studies are warranted to raise the level of evidence for robust clinical recommendations. Until that time, clinicians will need to continue to question current policies and adapt their daily practice to evolving scientific data.