There is increasing interest in addressing the ethical dilemma related to engagement of adolescents in public health research – especially in sexual and reproductive health. This points to the need to design and implement research that addresses the needs of adolescents including STDs and HIV, adverse pregnancy outcomes, violence and mental health. Decisions on when an individual has adequate capacity to give consent for research most commonly use age as a surrogate rather than directly assessing capacity to understand the issues and make an informed decision on whether to participate in research or not. Unfortunately, there is perception that adolescents participating in research are more likely to be coerced and may not fully comprehend the issues related to the risk they may be taking when engaged with research. This paper examines the various potential ethical issues that may impact stakeholders’ decision making when considering engaging adolescents in research and makes a case for lowering the age for consenting by adolescents. While some experts believe it is possible to extrapolate relevant information from adult research, studies on ethical aspects of adolescent participations in research are still needed, especially in the field of sexual and reproductive health where there are often differences in knowledge, attitudes and practices of adults when compared with adolescents. The particular challenges of applying the fundamental principles of research ethics to adolescent research, especially research about sex and sexuality, will only become clearer as more studies are conducted.