The aim of this study was to determine whether bacterial vaginosis (BV) is associated with a history of recurrent pregnancy loss. A total of 500 consecutive patients attending the Recurrent Miscarriage Clinic were screened for the presence of BV. In women who had had at least one late miscarriage BV was found twice as commonly (27/130; 21%) as in women who had had only early losses (31/370; 8%) (P<0.001). The difference was even larger (26 versus 8%) if women who had had term pregnancies were excluded. Moreover, BV was found three times more commonly in Afro-Caribbean women [17 (29%) of 58] than in Caucasian women [36 (9%) of 379] and, in both groups of women, BV was diagnosed at least twice as frequently in those with a history of at least one late miscarriage than in those who had experienced first trimester pregnancy losses only (P<0.001). The condition occurred twice as often among smokers than non-smokers and, in both groups, it was at least twice as common in women with a history of at least one late miscarriage as in those who had had early pregnancy losses only (P<0.001). However, the relationship between BV and smoking was independent of ethnic origin. Women who douched with chloroxylenol were mostly Afro-Caribbean and had BV more than twice as often as women who did not douche.