The identification of prognostic parameters in ependymomas remains an important but controversial issue in particular to the significance of histopathological features. Intracranial location is a rare presentation for adult ependymomas. DNA ploidy status and nuclear morphometric features of ependymomas are not well-established. We retrospectively studied the clinicopathologic features of 12 adult intracranial ependymomas and performed image cytometric DNA analysis with nuclear morphometry. The overall survival rate was 75%. Two cases were anaplastic ependymomas. Statistically, histology failed to demonstrate a correlation with clinical outcome or overall survival. DNA ploidy (p = 0.033), DNA index (p = 0.016) and 5c exceeding rate (p = 0.017) were statistically correlated with clinical outcome, but not correlated with overall survival. Nuclear morphometric features measured using 3 different data selection methods were not correlated with clinical outcome or overall survival. It is difficult to identify prognostic factors in a series of cases with limited number. The problem is complicated by the fact that the common criteria used for recognizing malignancy in gliomas are not completely reliable in ependymomas. Nuclear morphometric findings support the general impression that ependymomas are morphologically highly variable tumors. In spite of the small sample size of our series and other factors influencing survival such as the extent of resection and malignant histology, aneuploidy can be suggested as a promising factor, which may reflect potential aggressiveness of the tumor in adult intracranial ependymomas.