Background: In recent times, self-medication has been largely been aided by vigorous promotional adverts by pharmaceutical companies. Self- medication as an aspect of drug abuse is a threat to youths and adolescents, people take drug for many reasons, for example, for fun, escapism sensual stimulation and as a result of frustration. This study aimed to ascertain knowledge of dangers of self-medication among secondary school students. Methods: The descriptive cross-sectional survey was used to study 280 students aged 12-21 years in Anohachia South LGA. The subjects were selected simple random sampling. Data collected using a well-structured questionnaire were analyzed using Statistical Package for Social Sciences (version 15). Test of associations employed Chi-square statistical too with the level of significance taken at 5%. Results: Despite the fact that 75% respondents knew about self-medication, only 36% knew about dangers associated with self-medication. An association was established between knowledge of self-medication age, class, gender and religion (P=0.0038, 0.032, 0.047, 0.001 respectively). Conclusion: There is inadequate knowledge on dangers of self-medication among students, and knowledge was influence by gender.