Objective. The aim of this study was to compare buccal and vaginal mucosa with respect to their permeability to a potent carcinogen, benzo[a]pyrene. Study design. Six clinically healthy vaginal mucosa specimens (mean patient age +/- standard deviation, 52 +/- 13.4 years; age range, 37-69 years) and 6 buccal mucosa specimens (from 5 male patients and 1 female patient: mean patient age +/- standard deviation, 32 +/- 5.2 years; age range, 24-39 years) were obtained during surgery. In vitro flux rates of benzo[a]pyrene across specimens were determined through use of a flow-through diffusion apparatus. Analysis of variance, a Duncan multiple range test, and an unpaired t test were used to determine steady state kinetics and flux differences over time intervals. Results, No statistically significant differences were observed between the overall mean flux values of benzo[a]pyrene across the 2 kinds of mucosa. Conclusions. The findings further support the hypothesis that human vaginal mucosa can be used as a model for buccal mucosa in studies of permeability to various chemical compounds.