This study was conducted in April 2007 E.C in Ayer Tena Secondary School. The objective ofrnthis study was to explore the prevalence of substance abuse, identify the reasons why studentsrnabuse drugs, to see the highly abused drugs and the perceived effect of drug abuse among thernstudents. Respondents were randomly selected for the study. A total of 118 respondents (74 malernand 44 female) were selected to fill in a close ended questionnaire. From the total respondents,rnonly 114 (96.6%) completed the questionnaire properly and the non response rate was 4 (3.4%).rnThe analysis of results were based on the 114 respondents. The results were analyzed by usingrndescriptive statistics and inferenial statistics.Pilot study and Pretesting of the questionnaire wasrnconducted among 30 students that were not included in the actual study. Anonymous selfadministeredrnstructured questionnaire initially prepared in English version and later translatedrnto Amharic version was conducted in order to obtain the required information from thernrespondents. The finding in this study indicated the overall prevalence of substance abusernamong Ayer Tena secondary school students was 24.6%. The most commonly abused substancesrnas the finding shows, 5.90% smoke cannabis, 4.20% chew khat, and 0.80% drinks Alcohol, andrn0.80% smoke cigarettes. Alongside, the study indicated, most of the students abuse more thanrnone substance at the same time and Khat and Cannabis were the highly abused substance by thernstudents. There was no statistically significant association between gender and substance use.rnThe finding shows male students exposed to the problem than that of the female students.Arnstatistically significant association was found in socio demographic variables such as familyrndrug use and age. The minimum age range of the students resides between 15 - 16 yrs of agernwhich constitutes 86.18% of the participants. The result discloses family drug use have an effectrnon drug use of the students. Beside family influence, peer pressure has been found playing arnprofound influence for drug using behavior. Drug use behavior is more common with age matesrnthan with family members. As the result demonstrates, the student’s major source of money tornpurchase substances was their parents. The main consequence of drug use reported by thernstudents was encountering physical and emotional problems. This implies that drug use hasrnnegatively contributed to student’s education and relationships. Based on the findings of thernstudy, suggestions were made and social work implications and interventions wereforwarded