Background: Vaginitis is one of the most common causes of women's visits to a family physician and gynecologist. If untreated it may lead to serious complications. Objectives: To detect the prevalence of aerobic vaginitis among women of reproductive age attending at Family Medicine and Gynecology Clinics in Menoufia University Hospital, Egypt and determine the most common bacterial isolate and its virulence profile in both pregnant and non- pregnant women. Methodology: High vaginal swabs were obtained from 350 women (200 pregnant and 150 non pregnant) who visited Family Medicine and Gynecology Clinics in Menoufia University Hospital during the study period and suspected of having vaginitis. Identification of isolated micro-organisms was done by standard microbiological methods. Identification and antimicrobial susceptibility testing of the most common aerobic bacterial species isolated from vaginal samples were performed. Also, 15 fecal E. coli strains were isolated from healthy women. The prevalence of Virulence genes fim H, iucC, hly F, papC, afa, ibe A and cnf among Escherichia coli (E. coli) isolates was examined by multiplex PCR. Results: The prevalence of aerobic vaginitis was 43% in pregnant women and 26% in non-pregnant women. E. coli was the most common isolated aerobic bacterial spp. Antibiotic resistance of E. coli isolated from non-pregnant women was higher than those isolated from pregnant women with a highly statistically significant difference. Higher rate of virulence genes was detected among E.coli isolated from pregnant women when compared with those isolated from non-pregnant women with a highly statistically significant difference (P<0.001). Comparing virulence factors of total vaginal E. coli isolates (50) with fecal E. coli isolates (15), the vaginal E. coli strains harbored higher percentage of virulence genes than did fecal E. coli strains with a highly statistically significant difference (P<0.001). Conclusions: Escherichia coli from pregnant women with aerobic vaginitis is more virulent than those from non-pregnant women, thereby increasing possible maternal and neonatal complications.