The present study was conducted to find out whether there are some differences in plasma carnitine levels among young-, middle-, and old-aged normal Korean women. Daily food intake, body fat content, plasma lipids and carnitine levels were measured in 153 samples from 44 young (20-24 years old), 49 middle-aged (30-49 years old), and 63 old (65-85 years old) normal volunteers. The differences in concentrations of nonesterified acylcarnitine and acid-soluble acylcarnitine were not statistically significant among them. However, acid insoluble acylcarnitine (AIAC) level in plasma decreased with age. Moreover, total carnitine (TCNE) level in the young group was significantally higher than in old and middle-aged groups. Body fat content in the young group was significantly lower than in old and middle-aged groups. Plasma total cholesterol increased with age and triglycerides in the old group were significantly higher than in young and middle-aged groups. These results suggest that the higher levels of AIAC and TCNE in the young group may be a reflection of their lipid metabolic state, which is different from middle-aged and old groups.