It has recently been advocated that iron supplementation begin before childbearing. A key operational issue is timely identification of females prior to pregnancy. The purpose of this study was to examine factors associated with time to first pregnancy (FP) and adolescent pregnancy (AP). A cross-sectional survey was conducted in Gazipur, Bangladesh (April-May 2006) among ever married females aged <=50 y. Data on 603 females were analysed. Mean age was 32 y ± 9. Only 15% (7/47) of never pregnant females reported iron use in the past 6 mo. Mean age at marriage was 17 y ± 3 at marriage. 58% (322/556) of females were <=18 y at FP. Median time from marriage to FP was 12 mo (range: 0-408). Multivariate hazard analysis found risk of pregnancy increased by 13% for every y increase in age at marriage (p<0.0001) and decreased by 3% for every y increase in female’s current age (p<0.0001). Risk among medical contraceptive users was 58% of the risk among non-users (p=0.0001). Using multivariate logistic regression analysis the probability of an AP decreased by 3% for each y of marriage during adolescence (CI: 0.95-0.99), by 10% for every y increase in husband’s age at marriage (CI: 0.87-0.94), by 68% among female wage earners compared to non-wage earners (CI: 0.16-0.64) and by 50% among medical contraceptive users compared to non-users (CI: 0.30-0.85). In this population females are married at a young age with short time to FP intervals. Periconceptional iron supplementation programs should target adolescents and newly-weds.