OBJECTIVE: The aim of this study was to identify whether computed tomography-based morphologic parameters actually are correlated with the rupture status of anterior communicating artery aneurysms (ACoAAs). METHODS: A total of 167 patients with ACoAAs were treated in our neurosurgery department from May 2010 to May 2015, and the morphologic and clinical characteristics of 80 of them (50 ruptured and 30 unruptured) were analyzed retrospectively. Morphologic parameters were evaluated on the basis of 3-dimensional computed tomography angiograms and included neck diameter, maximum height, perpendicular height, aspect ratio, size ratio, aneurysm angle, vessel angle, flow angle, parent-daughter angle, aneurysm shape, number of aneurysms, variation of the A1 segment, and the direction of the aneurysm dome. RESULTS: The chi(2) test revealed that the anterior direction was associated with ACoAA rupture. The independent sample t-tests revealed that the parent-daughter angle and the size ratio were associated with ACoAA rupture. However, the binary logistic regression revealed that the size ratio was the strongest factor associated with ACoAA rupture. CONCLUSIONS: The anterior direction, parent-daughter angle, and size ratio between ruptured and unruptured ACoAAs were found to be statistically significant; they may be implicated in the rupture of ACoAAs, but the size ratio was the strongest factor that was correlated with rupture of ACoAAs based on binary logistic regression.