Context: Despite the renewed commitment of governments and actions taken in favor of contraception, its use is low in Benin while the unmet need for family planning remains high among women in union. This contributes to the increase in unwanted pregnancies, abortions and deaths of mothers and their infants. This article aims to highlight the factors associated with unmet need for family planning. Methods: Secondary analysis of data from the Demographic and Health Survey of Benin 2011-2012 edition covering 11680 women aged 15-49 in union was carried out using the binomial logistic regression method. Results: The spouse's fertility preference and age are associated with unmet need for birth spacing while the standard of living of the household influences unmet need in birth control. In addition, the age of the woman, the number of children born alive, her area of residence and her accessibility to health services also determine the two types of unmet need for family planning. Conclusion: Develop strategies to promote sexual and reproductive health by taking into account the influencing factors of unmet need for family planning.