This is a cross-cut study that was carried out with the objective of investigating the causes through which adolescents have provoked abortion, relating it to age and the type of school attended. The sample was calculated by taking into account the number of hospital admissions for post-abortion curettage. A semi-structured and anonymous questionnaire was used as a research instrument which was applied in ten schools randomly chosen among all schools, of Maceió (Alagoas, Brazil), to reach 12-19 years old female teenagers. The data were assessed by the Epi Info Program making use of odds ratio and a relative risk to verify any association among variables and a confidence interval at 95%. At a sample of 2,592 adolescents, 559 (21.6%) had an active sexual life, 182 (7.0%) informed to have been pregnant and 149 (26.7%) to have aborted. The fear of the parents' reaction, age, lack of support of the partner and pregnancy rejection were the explanation to stimulate abortion. Fear was the most mentioned cause in both types of school. Abortion was more mentioned in public schools, being significant and protective the risk of aborting before the age of 15. The fear of the parents' reaction as a frequent cause suggests the necessity for additional studies on sexuality and communication between parents and children.