Bacterial vaginosis (BV) is one of most common presentation in women of reproductive age, and its prevalence is relatively high in the obstetric population which is responsible for preterm delivery. The present study tried to explore the association of BV with preterm delivery, and included 100 pregnant women aged 15 to 35 years, between 28 36 weeks of gestation, with abnormal vaginal discharge and clinically suspected of BV, attending obstetrics outpatient department of BSMMU were selected for the study, divided into two groups based on Amsel clinical criteria (63 culture negative and 37 culture positive for BV). Mean ± SD age of BV negative and positive subjects was 24.59 ± 5.18 and 23.89 ± 4.77 years respectively (statistically no significant difference). Likewise, socioeconomic status, educational status and gravida did not show statistically any significant difference between groups. Significantly high number of BV positive women delivered prematurely (73%) compared to BV negative (25.4%) (p<0.001). Mean ± SD gestational age also differed significantly 37.49 ± 2.53 vs. 35.24 ± 2.33 weeks (p<0.001). Our study supported that abnormal bacterial colonization, indicative of bacterial vaginosis, is strongly associated with preterm delivery.