Bangladesh has undergone a considerable decline in fertility, despite the absence of conditions believed to be necessary for such reproductive changes. Indeed, Bangladesh is the only one among the world's twenty poorest countries where such a change has occurred. The paper examines the nature of fertility transition in Bangladesh, looks at the trends in contraceptive use and fertility, and identifies the major factors accounting for the fertility decline, despite poor socio-economic conditions. Two types of factors in the decline are: (a) positive factors which encourage eligible couples to contracept, and (b) negative factors which compel women to contracept, for spacing or limiting births. The effects of positive and negative factors on contraceptive use and fertility are analysed with data from a rural sample of 4,194 women from the 1993-94 Bangladesh Demographic and Health Survey (BDHS), 2,597 women from the MCH-FP Extension Project area, and 8,110 women from the Matlab MCH-FP Project area. Logistic regression is used in the analysis.Strong and highly significant effects of female education, female employment and access to media on contraceptive use and fertility have been found.