OBJECTIVE We investigated to determine whether colposcopic, histologic, and virologic parameters of cervical intraepithelial neoplasia are influenced by a patient's age. METHODS A cohort of 967 women with a mean age of 37.1 years underwent screening for detection of cervical intraepithelial neoplasia by colposcopy, cytologic examination, and testing for high-risk human papillomaviruses with the Hybrid Capture System (Digene, Silver Springs, Md) and a general primer and type-specific primer polymerase chain reaction system. Cervicography was used for documentation and reproducible evaluation of the colposcopic appearance of the cervix. In 86% of patients with trivial colposcopic changes of doubtful significance (100/116) and 89% of patients with colposcopic changes consistent with cervical intraepithelial neoplasia (89/99), punch biopsy specimens were taken for histologic evaluation. RESULTS In patients with trivial colposcopic changes of doubtful significance, histologically confirmed cervical intraepithelial neoplasia was almost as frequent (32%, 37/116) as in patients with colposcopic changes consistent with cervical intraepithelial neoplasia (43%, 43/99, difference not significant). The ratio between colposcopic evidence of cervical intraepithelial neoplasia and trivial colposcopic changes was 1.9 in patients <35 years old with cervical intraepithelial neoplasia, versus 0.5 in patients >/=35 years old with cervical intra-epithelial neoplasia (P =.005). Patients with trivial colposcopic changes of doubtful significance were older (median age 36 years) than were patients with colposcopic changes consistent with cervical intraepithelial neoplasia (median age 29 years, P =. 008). In patients with cervical intraepithelial neoplasia who had no or trivial colposcopic changes, the thickness of neoplastic epithelium was smaller (P =.008) and the number of cellular layers was lower (P =.01) than in patients with cervical intraepithelial neoplasia who had colposcopic changes consistent with cervical intraepithelial neoplasia. In patients <35 years old the rate of positive results for a high-risk human papillomavirus (P <.005) and the viral load (difference not significant) were higher than in women >/=35 years old. The rate of positive results for high-risk human papillomaviruses differed independently of age among patients with normal colposcopic findings, patients with trivial colposcopic changes of doubtful significance, and patients with colposcopic changes consistent with cervical intraepithelial neoplasia (P <.005). CONCLUSIONS In women >/=35 years old cervical lesions associated with intraepithelial neoplasia are thinner and thus less colposcopically conspicuous than those in women <35 years old. Patients >/=35 years old with acetowhite cervical lesions consistent with trivial changes of doubtful significance should therefore undergo punch biopsy for histologic evaluation.