Purpose: Disruption of sleep has great impact on quality of life. In children with a suprasellar tumor and hypothalamic-pituitary dysfunction, the circadian rhythm may be disturbed causing sleep problems. However, also other factors may influence sleep. Awareness of these different etiologies and careful history taking with appropriate additional diagnostics will aid in restoring sleep quality. Methods: We present the workup of 4 cases with a suprasellar tumor and disturbances of sleep initiation, sleep maintenance, and daytime sleepiness. In parallel, we developed a flowchart, to aid clinicians in the diagnostics of sleep problems in children after treatment for a (supra) sellar brain tumor. Results: All four patients, known with hypopituitarism, presented with sleep complaints and increased daytime sleepiness. In all four, the cause of sleep problems showed to be different. In the first case, sleep evaluation revealed a severe obstructive sleep apnea, whereupon nocturnal ventilation was started. The second case revealed poor sleep hygiene in combination with an obsessive compulsive disorder. Sleep hygiene was addressed and psychiatric consultation was offered. Dexamphetamine treatment was started to reduce her obsessive compulsive complaints. The third case showed a delayed sleep phase syndrome, which improved by educational support. The fourth case revealed a secondary organic hypersomnia for which modafinil treatment was started. Conclusion: Sleep disturbances in children with hypopituitarism due to a (supra) sellar tumor can have different entities which require specific therapy. Awareness of these different entities is important to enable appropriate counseling. Referral to an expertise sleep center may be advised, if standard educational support is insufficient.