In a feasibility study using a prototype, lateral-flow test for human papillomavirus type 16, 18, and/or 45 (HPV16/18/45) E6 oncoproteins, 51 of 75 (68%; 95% confidence interval [95% CI] of 56 to 78%) of HPV16/18/45 DNA-positive specimens from women with a diagnosis of CIN3+ (cervical intraepithelial neoplasia grade 3+ or cervical cancer) tested positive for HPV16/18/45 E6 oncoprotein. None of 16 (95% CI of 0 to 37%) HPV16/18/45 DNA-positive cervical specimens from women with a negative or CIN1 diagnosis tested positive for HPV16/18/45 E6 oncoprotein.