This study explored the patterns and socio-demographic correlates of sexual initiation, subsequent risk behaviors, and condom use among secondary school youth across Ethiopia. A total of 1,102 students were selected on convenience basis from five urban schools (in Baher Dar, Dessie, Awassa, Jimma, and Dire Dawa) and surveyed about their sexual and preventive behaviors using an extensive questionnaire. Data were analyzed using bivariate and multivariate statistical procedures. One third (33.3%) of the youth reported to have had sexual intercourse prior to the study. Mean age of sexual initiation was 15.3 (SD = 2.5) years. Two-thirds of the sexual initiations were unprotected and some occur with higher risk groups, including much older (15.5%) or casual/commercial sex partners (9.1%). Multi-partnered sex (52.7%) and sex with casual (30.4%) or commercial (25.3%) partners were the most commonly reported lifetime risk behaviors. Although 56.7% of the youth ever used condoms, only less than half of these used them regularly. On the positive note, 83.4% of the youth expressed intentions to use condoms in the future. Socio-demographic characteristics, particularly gender, location, and age, were significantly correlated with sexual and preventive behaviors. Implications of these findings to health education programs for youth are discussed.