Objective: To assess the prevalence of antibiotic misuse among boarding secondary school students in Dar es Salaam.Methodology: This descriptive cross-sectional study was conducted over 3-month period amongst boarding secondary school students.A randomized sample of students was recruited from at least 3 secondary schools from each of the three municipalities of Dar esSalaam region. Questionnaire with both closed-and open-ended questions was used for data collection in which socio-demographiccharacteristics, knowledge of ATBs, sources of prescription, procurement of ATBs, infections for which ATBs were used, andantibiotic therapy compliance were assessed. The collected data were analyzed using SPSS/PC+ version 15.0 computer package.Results: A total of 424 randomly selected students with a mean age of 20 years were interviewed, of those 150 were females and 274 were males. Majority of the respondents (74%) have had heard of ATBs, however only 105(25%) respondent described them correctly. Prevalence of antibiotic usage among the students was high (69%). Of 293 students who have had used ATBs, 73% of them had procured the drugs on prescription; 170 (58%) respondents used the ATBs for non-microbial infections/diseases, only 183(62%) were compliant to antibiotic therapies (ABT), while 226(77%) admitted to have had shared ATBs with friends/relatives whenever deemed necessary. Of those who had procured ATBs without prescriptions, 66% of them obtained the drugs from pharmacies.Conclusion: The study revealed inadequate knowledge on ATBs among the respondents and that pharmacies played a major role on easy availability of ATBs as over-the-counter (OTC) drugs attributing to high rate of irrational use of ATBs. We recommended that health care providers should succinctly explain to patients the importance of ABT compliance and adverse effects of non-compliance. Regulatory authorities should re-enforce the laws on sales of ATBs by prohibiting their availability as OTC drugs.