In Ethiopia, there is no reliable information about sexualrnbehaviours and contraception usage of adolescent students. Thernincidence of morbidity and mortality of young female students duernto induced abortion of unwanted pregnancy is increasing. This isrna cross sectional study which was conducted to assess thernknowledge, attitude, and practice of high school students inrnHarar town toward family planning. A total of 1674 students fromrn11th and 12th grades aged between 15 and 26 years were interviewedrnby means of self administered anonymous questionnaires. Thernrespondents were 887(52.9%) males and 787 (47.1%) females.rnThe major finding of the study were that 20% of females andrn65% of the males admitted to having had sexual intercourse. Thernaverage score of knowledge and attitude items about FP was 8.3 outrnof 13 and 7.3 points out of 10 respectively. Among those who hadrnsexual intercourse, 60.3% of the females and 67.1% of the malesrnreported that they knew at least one type of contraceptive methods.rnOf the sexually active females, 59.6% were using one of therncontraceptive methods. However, the majority (76.3%) were using therncalender method and only 19.4% said they used birth control pillsrnor condoms. One fifth of the male respondents (20.0%) usedrncondoms. A total of 21.8% of females who are sexually experiencedrnhave been pregnant, and 55.9% of them have terminated the pregnancyrnby means of induced abortion.rnviirnThe main source of eM information was mass media (31. 3 %)rnfollowed by school (24.2%). More than half of the respondentsrn(53.3%) have an intention to use contraceptive methods in thernfuture . The majority (93.7%) of the respondents approved thernprovision of information in school about contraception and STDs.rnIn our findings the knowledge of the students was modest andrnthe practice of contraceptive utilization was low. This informationrncan be used in planning family life education programs.rnviii