Recent advances in neuroimaging techniques have resulted in more frequent detection of unruptured intracranial aneurysms. Regardless of the method employed, most interventions to treat lesions have low morbidity and mortality rates. Recently, some studies have suggested that changes in cognitive status are one complication of microsurgical treatments. However, no study to date has performed any behavioral analysis. Moreover, cognitive assessment beyond 12 months after surgical intervention is missing. The current study sought to evaluate the long-term impact of clipping on the behavioral and cognitive functions of patients with unruptured intracranial aneurysms. Method: A within-subjects prospective clinical trial was performed to evaluate 40 patients who underwent microsurgical clipping for incidental unruptured intracranial aneurysms. The participants underwent a full neuropsychological evaluation during the preoperative period, at 3 months after surgery and at 3 years after surgery. Paired Student¿s t tests and an ANOVA, followed by a Bonferroni post hoc test, were used to examine group differences. Results: The cognitive and behavioral test performance of the patients did not deteriorate during either the short or the long term following intervention. Moreover, the patients¿ clinical and demographic characteristics did not predict behavioral or cognitive changes, and neither the surgical approach nor the topography, multiplicity, or size of the aneurysms affected the results. Conclusions: In either the short or the long term following clipping for patients with incidental unruptured intracranial aneurysms, behavioral and cognitive functions had no significant change from baseline. The intervention demonstrated high efficacy and was associated with a low morbidity rate.