Background: In 1990, a study of the reproductive habits and cervical pathology in women of the Qashgha'i nomadic tribe, resulted in a high prevalence of cervicitis. This led us: to explore the likely infectious agents responsible for such a high prevalence; to assess the difference in cervicitis rates between nomadic and non-nomadic populations in the same area ; to determine the risk factors for and the relationship between cervicitis and bacterial vaginosis (BV). Method and materials: In 1996-1997 a study was carried out of 839 married women of the QashghaT tribe, 274 of the Lor nomadic tribe, and 388 non-nomadic urban women in southern Iran. A gynaecological examination. Pap smear and vaginal secretion for assessing cervicitis and BV by gram staining respectively were performed. Data were analysed by univariate and multiple logistic regression first with cervicitis as the outcome, then with BV as the outcome. Backward stepwise regression was used to assess multivariate effects on risk of cervicitis. Results: Overall, the prevalence of cervicitis was 88% among Qashgha'i women, 85% in the Lor and 71% in the urban population. There was a significantly lower number of cervicitis cases in those over 40 years old (p = 0.004) and in those with a history of postpartum bleeding in Qashgha'i women. In the Lor tribe, the predictors were an increased risk after more than four pregnancies (p < 0.01) and the use of any contraception (p < 0.002). Among the urban population, the risk of cervicitis was increased with the use of oral contraceptive previously (p = 0.03) or currently (p = 0.01). BV was strongly associated with cervicitis, with a relatively high attributable risk. Discussion: Both sexual and childbirth exposures may be associated with cervicitis in these populations. We found a very strong positive association between bacterial vaginosis and cervicitis. Bacterial vaginosis was a powerful risk factor for cervicitis even after adjustment for other risk factors for cervicitis. Attributable risks were also high, suggesting that bacterial vaginosis may be implicated in 60% of cases of severe cervicitis cases. Both cervicitis and bacterial vaginosis are known to be associated with chlamydia. We found a strong positive association between high levels of histiocytes and presence of cervicitis (RR=8.69). Even taking account of the imprecision of this as an indicator of chlamydial infection, it is strongly suggestive of chlamydia as a major cause of this high rate of cervicitis. Recommendation: In terms of the reproductive health status of the populations studied, the cervical inflammation is not only widespread, but also had a strong association with BV in all three populations. Abscence of dyskariosis, a high level of bacterial vaginosis, a strong association between cervical inflammation and BV, and a strong positive association between high level of histiocytes and the presence of cervicitis suggest that chlamydia is largely responsible for the cervicitis in the population. This should be verified by definitive testing and rectified by treatment programmes.