Background: Few studies have examined women’s values and preferences about contraception. Interventions that assist women with contraceptive decision making have potential to increase value-concordant decisions and improve continuation and satisfaction, thereby decreasing unintended pregnancy. In this study, we used a mixed-methods approach to identify the values and preferences important to women in contraceptive decisions with the ultimate goal of developing a web-based contraceptive decision aid. Methods: We conducted focus groups of reproductive-age women to explore themes around sex, pregnancy, and contraception. We also administered a written survey to women seeking contraception who were enrolling into a contraceptive study. We then used the results of the formative research to develop a computerized contraceptive decision aid. The decision aid incorporated the themes into a value-clarification exercise which asked women to select the three most important factors. We tested our computerized decision aid with women seeking contraception and conducted in-depth interviews with a subset to obtain feedback about the aid. Results: There were 44 women who participated in 12 focus groups. We also administered a written survey to 2590 women enrolling into the Contraceptive CHOICE Project (CHOICE). Respondents in both the qualitative and quantitative portions of the study were racially and socioeconomically diverse. Multiple themes emerged as important in making decisions about contraception. Similar themes were identified in both the quantitative and qualitative components – the most common themes were effectiveness of the method; affordability of the method; concerns about safety and side effects including change in bleeding patterns; and not having to remember to use the method regularly or that the method is long-lasting; There were 733 women CHOICE participants who completed the computerized decision aid – 28 of these also participated in in-depth interviews. Feedback from the in-depth interviews was positive, but many women expressed difficulty in having to identify only three factors that influenced their contraceptive decisions. Conclusion: Contraceptive decision making is complex and multiple values and preferences influence women’s decisions. A randomized trial is needed to evaluate whether a web-based decision aid will assist women in making a value-concordant decision and improve continuation and satisfaction.