In this paper, we describe calcification in the choroid plexus of lateral ventricles with a discussion of the frequency of occurrence in categories of age, sex, and laterality, and its correlation with pineal calcification. The study was conducted on 2877 consecutive cases (1450 males and 1427 females) that had plain CT scanning. Three types of CT scanners (SCN-200, Somatom 2 and TCT-10 A) were used. This series included only calcification of the choroid plexus in the trigone of the lateral ventricles (glomus). Calcification was found in none of the cases aged under 9 years, 5.9% aged from 10 to 14 years and 17.4% aged from 15 to 19 years. The calcification rate strikingly increased with increasing age of the cases. It was 51.5% of cases between 30 and 39 years of age. After that, the increasing rate of calcification gradually decreased, however calcification was found in 74.4% of cases aged over 80 years. The calcification rate was 64.7% in our total series of cases aged over 20 years, 66.5% aged over 30 years and 70.7% aged over 50 years. The calcification rate of male cases was greater than that of females in the age group of over 15 years. However, there was a significant difference only in the cases ranging from 60 to 79 years of age. The initial incidence of male cases was found at the age of 12 years and that of females at the age of 16 years. There was no difference in calcification on right and left sides.(ABSTRACT TRUNCATED AT 250 WORDS)