Aiming at being part of the discussion about the cognitive functioning of patients with arachnoid cysts (AC) and the value of neuropsychological testing in these patients, we present our study in which we investigated the cognitive functioning of 32 children with ACs of the middle cranial fossa. We compared the Stanford Binet 5 (SB 5) results obtained by the patients with the population mean values and analysed the relation between the patients' clinical details and the results of SB 5. The main conclusions of this research are: (1) In SB 5 tasks, the tested group performed worse than the population mean, which could be related to AC of the middle cranial fossa. Deficits concern especially visuospatial reasoning, quantitative reasoning, and knowledge. The obtained results indicate the coexistence of cognitive impairment and AC of the middle cranial fossa. (2) In patients with AC, neuroimaging information has only limited predictive ability regarding cognitive syndromes. (3) The complaints reported in the interview are not necessarily objectively reflected in the clinical assessment. Neuropsychological assessment should be part of the management of all patients with AC. (4) Cognitive deficits in patients with AC may become more pronounced with age. Accordingly, increasing school difficulties in these patients should be expected. In light of the above, there is a clear indication of the need for neuropsychological support and support in school functioning for patients with AC. (5) Neuropsychological control in patients with AC is crucial not only with regard to treatment decisions but primarily for monitoring school performance and providing these patients with adequate neuropsychological and psychological support.