Background Young Ghanaian women experience high rates of unmet need for contraception and unintended pregnancy, and face unique barriers to accessing sexual and reproductive health services. This study provides a comprehensive national analysis of young women’s contraceptive and abortion practices and needs. Methods In 2018, we conducted a nationally representative survey of women aged 15–49, including 1039 women aged 15–24. We used descriptive statistics, multivariable logistic and multinomial regression to compare young versus older (25–49 year-old) women’s preferred contraceptive attributes, reasons for discontinuing contraception, quality of counseling, use of Primolut N-tablet, method choice correlates, and friends’ and partners’ influence. We also examined youth’s self-reported abortion incidence, abortion methods, post-abortion care, and barriers to safe abortion. Results Among Ghanaian 15–24 year-olds who had ever had sex, one-third (32%) were using contraception. Compared to older women, they had higher desires to avoid pregnancy, lower ever use of contraception, more intermittent sexual activity, and were more likely to report pregnancies as unintended and to have recently ended a pregnancy. Young contraceptors most commonly used condoms (22%), injectables (21%), withdrawal (20%) or implants (20%); and were more likely than older women to use condoms, withdrawal, emergency contraception, and N-tablet. They valued methods for effectiveness (70%), no risk of harming health (31%) nor future fertility (26%), ease of use (20%), and no effect on menstruation (19%). Infrequent sex accounted for over half of youth contraceptive discontinuation. Relative to older women, young women’s social networks were more influential on contraceptive use. The annual self-reported abortion rate among young women was 30 per thousand. Over half of young women used abortion methods obtained from non-formal providers. Among the third of young women who experienced abortion complications, 40% did not access treatment. Conclusions Young people’s intermittent sexual activity, desire for methods that do not harm their health, access barriers and provider bias, likely contribute to their greater use of coital-dependent methods. Providers should be equipped to provide confidential, non-discriminatory counseling addressing concerns about infertility, side effects and alternative methods. Use of social networks can be leveraged to educate around issues like safe abortion and correct use of N-tablet., Plain English summary Young Ghanaian women can experience difficulties accessing sexual and reproductive health services, and many are not using contraception despite wanting to avoid pregnancy. To better understand their needs, we describe their preferences and behaviors around contraception and abortion. We surveyed a nationally representative sample of women aged 15–49, and compared young (15–24) versus older (25–49) women’s contraceptive preferences, reasons for stopping contraception, quality of counseling, friends’ and partners’ influence on contraceptive use, and use of abortion. One-third of 15–24 year-olds who ever had sex were using contraception. Compared to older women, young women’s pregnancies were more likely to be unintended and to end in abortion. Young women most commonly used condoms, injectables, withdrawal or implants; and were more likely than older women to use condoms, withdrawal, emergency contraception, and Primolut N-tablet. They preferred methods that were effective, did not harm their health or future fertility, were easy to use, and did not disrupt their menstrual cycle. Over half of young women who stopped contraception did so because they were not having sex regularly. Friends had more influence on contraceptive use among young women than older women. Each year on average, there were 30 abortions per 1000 young women. Over half of young women who had abortions used methods from non-formal providers, and 40% of those who had complications did not get treated. Providers should be equipped to provide confidential, non-discriminatory counseling about contraceptive side effects and options. Social networks can be used to educate women about safe abortion.