OBJECTIVE In vitro, Candida albicans has demonstrated the ability to inhibit replication of selected bacteria. Little information exists on the impact of C. albicans on the vaginal bacterial flora in vivo. The purpose of this study is to identify the coexisting bacterial flora when C. albicans is isolated from vaginal cultures submitted to a hospital-based testing facility for reasons other than vulvovaginitis. METHODS All specimens (240) received from ambulatory care clinics over a six-month period were cultured for aerobic and anaerobic bacteria and Candida species. Those specimens submitted for cervicitis, vaginitis, or vaginal discharge and those from which yeasts other than C. albicans were isolated were eliminated. To control for sample biases, a subgroup composed of all pregnant women for whom cultures were done as screening procedures was similarly studied. Chi-square analyses, comparing the prevalence of individual bacteria isolated with and without the presence of C. albicans, were done for all study populations using SPSS for Windows software (1994). RESULTS Two hundred and forty consecutive specimens were bacteriologically analyzed. Of the 220 vaginal samples used in the study, C. albicans was isolated in 44 instances (20%). Neither the presence of the lactobacilli nor the presence of Gardnerella vaginalis markedly influenced the isolation rate of C. albicans. The group B streptococci had a greater probability of coisolation when C. albicans was present (27.3% verses 16%), but this was not statistically significant (P < 0.8). Dissociation between the presence of C. albicans and the coisolation of Peptostreptococcus species and anaerobic gram-positive cocci and/or bacilli was noted (P < 0.0819), while the incidence of gram-positive aerobic bacilli was reduced in the presence of C. albicans (30/176 [17.1%] versus 6/44 [13.6%]), this reduced incidence was not statistically significant. Isolation data of the subgroup of pregnant women supported these observations. CONCLUSIONS Within the limitations of the study, statistically, the data suggests that an inverse relationship exists between the presence of C. albicans and recovery of Peptostreptococcus and anaerobic gram-positive cocci and bacilli.