BackgroundAdolescents face significant barriers to contraception access and utilization that result in adverse health effects of early pregnancy and childbirth. Unsafe abortions continue to occur partly due to failure to prevent pregnancies, with Sub-Saharan Africa contributing the most significant burden of all unsafe abortions among young people globally, of which a quarter occurs in those aged 15–19 years. We aimed to conduct a systematic review of the contraceptive and abortion knowledge, attitudes and practices of adolescents in low and middle-income countries to increase the understanding of the sexual and reproductive health dynamics that they face.MethodsLiterature searches from 6 databases; PubMed, Science Direct, Google Scholar, BioMed Central, CINAHL, MEDLINE, were conducted, covering the period from 1970 to 2016 and concerning the adolescents aged 15–19 years and 21 studies were read and analyzed using thematic analysis.ResultsLimited knowledge about sexual and reproductive health among adolescents was a significant cause of reduced access to contraception and safe abortion services, especially among unmarried adolescents. Reduced access to reproductive health services for some resulted in extreme methods of contraception and abortion such as the use of battery acid and crushed bottles. Despite all adolescents having limited access to information and services, girls faced more consequences such as being blamed for pregnancy or dealing with the effects of unsafe abortions. Parents, health workers, and teachers were cited as trusted sources of information but often received the most information from peers and other family members instead, and the girls mostly confided in their aunties, cousins and peers while the boys resorted to peers, media and even pornography.ConclusionThe reported observations suggest severe limitations in the access to safe and effective methods of contraception and safe abortion services. There is a need for an urgent response in reducing the “unmet needs” for contraception and to improve access to contraception, abortion information, and services in this group. Interventions which target the involvement of parents and teachers should be considered, to carry one wholesome message to the adolescents.