We studied interobserver variability in the proportions of human papillomavirus (HPV)-positive results for atypical squamous cells of undetermined significance (ASCUS) and atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H) diagnoses among 5 pathologists from the me laboratory during a 2-year period. These proportions were compared with individual pathologist's ASCUS/squamous intraepithelial lesion (SIL) ratios. Of 1,299 ASCUS diagnoses, 32.3% had HPV testing; 49.4% were HPV+. Positive findings by individual pathologists ranged from 38% to 67% (P = .057). There was a difference in the proportions of high risk HPV results for individual pathologists (P < .001). For the pathologist who diagnosed 38% (23/61) of samples as HPV+, the ASCUS/SIL was 0.58; the pathologist who diagnosed 67% (28/42) as HPV+ had a ratio of 1.02. Of the ASC-H diagnoses, 32.9% were tested for HPV; 63% (46/73) were positive. Although the HPV+ proportion by pathologist ranged from 54% to 83%, no significant differences were identified. Within the me laboratory, interobserver variability exists in the proportions of HPV positivity for ASCUS and ASC-H interpretations.