Because the pineal gland produces melatonin, it is suggested to be involved in the regulation of sleep and circadian rhythm, though there is scant proof of this. Tumors of the pineal gland are rare and various in terms of histological and biological malignancy. We evaluated the occurrence of subjective sleep disturbances in nine patients who underwent a pinealectomy due to pineocytoma WHO°I without additional therapy.Patients with intracranial low-grade lesions and patients without a craniotomy who underwent a microscopic lumbar discectomy were matched to our study group by gender, age, and date of surgery. We used standardized sleep questionnaires on sleepiness during the daytime, sleep disturbances, and general pathologic sleep patterns.Patients who underwent a craniotomy either without a pinealectomy (7.2 ± 2.0 points) or with a pinealectomy experienced increased sleep disturbances (6.6 ± 1.3 points) compared to patients who had a lumbar discectomy (2.8 ± 0.4 points), according to the Pittsburgh Sleep Quality Index (PSQI) (p 0.05). Moreover, sleep disturbances as measured by the insomnia severity index (ISI) were most pronounced in patients who underwent a craniotomy without a pinealectomy (10.4 ± 3.1 points) compared to patients who underwent a pinealectomy or discectomy (5.9 ± 1.9 and 3.3 ± 1.3 points).Pinealectomy itself did not cause specific sleep impairment, but craniotomy in general did. This interesting and clinically relevant finding needs further investigation.