Unintended pregnancy is a serious concern in reproductive health which needs to be addressed. Analyzing 717 pregnant women extracted from the Bangladesh Demographic and Health Survey 1999-2000, this study identified that unwanted pregnancy is significantly associated with higher numbers of living sons (P<0.001), longer marital duration (P<0.05), exceeding desired family size (P<0.001), use of contraception (P<0.01), and breastfeeding practice (P<0.05). For mistimed pregnancy, higher age (P<0.05), breastfeeding practice (P<0.01), exceeding desired family size (P<0.01), pregnancy termination (P<0.05), and having last birth during last three years (P<0.001) were significant. Since unintended pregnancy is strongly associated with exceeding desired family size, a multidimensional approach may be needed through the family planning, health and educational sectors in Bangladesh to maintain desirable family sizes.