Background: A clear connection has been established between arachnoid cysts (ACs) and the evolution of idiopathic intracranial hypertension (IIH), a connection, which is presently not well understood. Cerebrospinal fluid (CSF) is an integral element of this condition. Little is known about either the influence of AC on CSF hydrodynamics or the specific nature of CSF, which contributes to the complex pathology of IIH. Case Description: This study aimed to chronicle in detail four patients with previously treated intracranial ACs, who developed persistent IIH. This series and review aims to identify and qualitatively analyze the multiple constituents, which could possibly elucidate the intrinsic relationship between arachnoid cyst-induced IIH and CSF hydrodynamics. A retrospective analysis of the medical records of four patients admitted to the institution’s neurosurgery department during the period of 1994–2013 was completed. This study investigated discernible aspects linking CSF pathophysiology with the development of IIH in AC patients. Four male patients, ranging from 3 to 44 years of age at presentation, had a left-sided arachnoid cyst treated surgically. All four patients subsequently developed IIH. Three patients remain persistently symptomatic. Conclusion: IIH associated with AC is a hydrodynamic disorder. The full discovery of its fluctuant pathophysiology is the only way to identify an effective standard for the management and treatment of this condition.