Sixteen cases of symptomatic arachnoid cyst in elderly patients (> 65 years of age) including of our own case are considered and their clinical and therapeutic features compared with those of the larger series comprising younger patients. From this study, no clinical differences emerged between arachnoid cysts in elderly patients and those of their younger counterparts. Surgical treatment was confirmed as being necessary for a good outcome in this age group when the cysts became symptomatic.