This study aims to quantify the prevalence of forced sex, pressured sex, and related pregnancy among adolescent girls and young women in five low- and middle-income countries. Nationally representative, cross-sectional household surveys were conducted in Haiti, Malawi, Nigeria, Zambia, and Uganda among girls and young women aged 13 to 24 years. A stratified three-stage cluster sample design was used. Respondents were interviewed to assess prevalence of sexual violence, pregnancy related to the first or most recent experience of forced or pressured sex, relationship to perpetrator, mean age at sexual debut, mean age at pregnancy related to forced or pressured sex, and prevalence of forced/coerced sexual debut. Frequencies, weighted percentages, and weighted means are presented. The lifetime prevalence of forced or pressured sex ranged from 10.4% to 18.0%. Among these adolescent girls and young women, the percentage who experienced pregnancy related to their first or most recent experience of forced or pressured sex ranged from 13.2% to 36.6%. In three countries, the most common perpetrator associated with the first pregnancy related to forced or pressured sex was a current or previous intimate partner. Mean age at pregnancy related to forced or pressured sex was similar to mean age at sexual debut in all countries. Preventing sexual violence against girls and young women will prevent a significant proportion of adverse effects on health, including unintended pregnancy. Implementation of strategies to prevent and respond to sexual violence against adolescent girls and young women is urgently needed.