Objective: The purpose of this study was to assess the in vivo optical detection of high-grade cervical intraepithelial neoplasia (2/3+) on the whole cervix with a noncontact, spectroscopic device. Study design: Cervical scanning devices collected intrinsic fluorescence and broadband white light spectra and video images from 604 women during routine colposcopy examinations at 6 clinical centers. A statistically significant dataset was developed of intrinsic fluorescence and white light-induced cervical tissue spectra that was correlated to expert histopathologic determination. On the basis of a retrospective analysis of the acquired data, a classification algorithm was developed, validated, and optimized. Results: Intrinsic fluorescence, backscattered white light, and video imaging each contribute complementary information to diagnostic algorithms for high-grade cervical neoplasia. More than 10,000 measurements that were made on colposcopically identified tissue from >500 subjects were the basis for algorithm training and testing. Algorithm performance demonstrated a sensitivity of approximately 90%. This performance was confirmed by various training methods. With the use of a multivariate classification algorithm, optical detection is predicted to detect 33% more high-grade cervical intraepithelial neoplasia (2/3+) than colposcopy alone. Conclusion: Full cervix optical interrogation for the detection of high-grade cervical intraepithelial neoplasia is feasible and appears capable of detecting more high-grade cervical intraepithelial neoplasia than colposcopy alone. With the use of this classification algorithm, a multisite, randomized controlled trial is underway that compares the combination of optical detection and colposcopy versus colposcopy alone. © 2004 Elsevier Inc. All rights reserved.