To review the cytologic criteria used in the diagnosis of bacterial vaginosis cases [Bv (+)], 2,841 Papanicolaou-stained vaginal smears were examined cytologically. Clue cells and other cytologic findings were observed in 94 of 2,841 (3.30%) vaginal smears. To detect Bv(+) cases, 94 vaginal smears were screened again. Clue cells, profuse free cocci among cornified type epithelial cells, absence of PMNLs, and vaginal Lactobacilli were detected in 43 of 94 (45.74%). The observation of free cocci which resembled a nebulous appearance was detected first in this study. These four cytologic criteria strongly suggested Bv(+) cases (n = 43). Although clue cells were seen in 51 of 94 (54.25%) vaginal smears, due to the presence of abundant PMNLs, metaplastic cells, vaginal Lactobacilli, and some infectious agents, mainly Trichomonas vaginalis and yeasts, they were considered bacterial vaginosis negative [Bv(-)]. It was postulated that 51 vaginal smears might be aerobic vaginitis. In conclusion, if vaginal smears contain profuse PMNLs, some infectious agents, and metaplastic cells, and even clue cells have been observed they are not accepted as Bv(+) cases. Diagn. Cytopathol. 2003;29:156-159. (C) 2003 Wiley-Liss, Inc.