Objective: Early sexual debut increases youth exposure to risky sexual behaviors, STIs including HIV/AIDS, and unsafe abortion. There is study limitation on this speci c issue on the study area. Therefore, this study aimed to determine the prevalence and associated factors of early sexual debut among preparatory school students in Gondar town, North West Ethiopia. Results: From a total of 797 students, 750 respondents complete the questionnaire giving a response rate of 94.1%. About 20.5% with 95%CI (17.6, 23.3%) of the respondents had early sexual debut. Had lesson on sexuality education (AOR=2.14, 95%CI 1.15, 3.98), drinking alcohol (AOR= 14.5, 95%CI 7.81, 27.22), had good parental monitoring (AOR=3.6, 95%CI 1.8, 7.45), had discussion on sexual issues with parents (AOR=3.05, 95%CI 1.04, 8.88), and had good academic achievement (AOR=4.2, 95%CI 1.72, 10.26) were found to be signi cantly associated with early sexual debut. Sexual education programs at earlier life may help to delay sexual debut for school youths and is recommended to incorporate it in the curriculum.