The natural history of arachnoid cysts is still a topic of debate in the medical literature and important to the neurosurgeon who intends to manage these cases. This article consists of a review of the literature available in the main digital libraries with wide access. This search resulted in six studies in which the developmental aspects of patients with this condition were specifically investigated. The analysis of those articles allowed us to conclude that the main and possibly only proven risk factor for cyst enlargement is age below five years, while among patients above this age group we can expect a benign evolution.