The study utilized a quasi-experimental research design to address the problem on the increasing incidence of teenage pregnancy through determining the effect of adolescent pregnancy lecture and interactive discussion on the knowledge and attitude of grades 9 and 10 female students and their mothers in Panagaan National High School, Mahayag, Zamboanga del Sur. Respondents included were 93 female students and 59 mothers of female students. A pre-test was given before the intervention and post-tests were given immediately after (post-test 1), 5 weeks after (post-test 2) and 10 weeks after (post-test 3) using a self-administered questionnaire. Results showed that there were increase in the number of female students and their mothers who passed from pre-test to post-tests. Using paired t test to analyse, mean scores of female students improved from 7.5484 to 10.2151 to 9.8925to 9.2581 with p value <0.05. Mean scores of mothers of female students also improved from 4.2542 to 6.1186 to 6.2034 to 5.8136 with p value <0.05. Female students reached the passing mean score of 9 hence, showed effectiveness of study, but for their mothers, passing mean score was not reached hence, intervention was not effective to mothers. As observed, almost all scores had minimal decreased on post-test 3, hence knowledge decay was noticed. Attitude of respondents was analysed using frequency distribution and Wilcoxon signed rank test. It showed that there were improvements on the attitude of female students against teenage pregnancy problems should be solved by other institutions; is willing to commit premarital sex as long as boyfriend will not leave, against premarital sex will be approved as long as studies is not neglected, against risk of engaging in premarital sex and talking to their mothers regarding sex-related matters. And improved their attitude towards premarital sex does not prove love, can affect studies; can add problems to the family, only for married couples and premarital sex does not prove that they are better than anyone. Improvement on the good attitude of their mothers was noted specifically against their daughters’ act of premarital sex even if they are ready to face the consequences, towards not allowing their daughters on a boy-girl relationship during high school and belief that premarital sex is wrong.

Keyword: Adolescent Pregnancy