OBJECTIVE: To determine a guideline on the cytologic diagnosis of ASCUS and to develope the relationship between cervical ASCUS and the eating habits in asymptomatic women. STUDY DESIGN: A total of 222 women with a cytologic diagnosis of ASCUS favoring either reactive change or squamous intraepithelial lesion(SIL) were evaluated by repeated Pap smear and colposcopy directed biopsy respectively. At the same time, eating habits of them were obtained by the questionnaire. RESULTS: Among the 157 women who had a cervical cytologic diagnosis of ASCUS favoring reactive change, 133 women(84.7%) were normal by repeated smear and/or cervical tissue biopsy. Twenty four(15.3%) of 157 women had squamous intraepithelial lesion. Among the 65 women who had a cervical cytologic diagnosis of ASCUS favoring SIL, 26(40%)were normal by repeated smear and/or cervical tissue biopsy. Thirty nine(60%) of 65 women had SIL. The confirmed SIL group showed the eatig habits of increased intake of processed food(6.67%).The other reactive group was lower(2.56%). CONCLUSION: A cytologic diagnosis of ASCUS favoring reactive change was associated with a very low risk of haboring SIL. But the woman whose initial smear showed ASCUS favoring SIL was associated with a relatively high risk of harboring SIL(p<0.001). Therefore, the woman whose smear showed ASCUS favoring SIL requires further active management even in the presence of a normal repeated pap smear. The ASCUS group favoring SIL showed the habits of increased dietary intake of processed food(P<0.05). Further study with large number of patients seems warranted.