This study was conducted to describe the self-efficacy, English proficiency, and teaching effectiveness of teachers teaching English in the public secondary schools of the Division of Ilocos Norte. Specifically, it examined the relationships among the teacher respondents’ socio-demographic characteristics, their level of self-efficacy, English
proficiency, and teaching effectiveness. Also, implications related to the teaching of English as a second language were drawn. The study utilized the descriptive-correlational method using survey questionnaires, classroom observations and interviews. Data were taken from the public secondary schools in the division of Ilocos Norte. Results of the study reveal significant relationships among teachers’ socio-demographic characteristics, level of self-efficacy, English proficiency, and teaching effectiveness. Evidence in this study about the relationship among the variables highlights the importance of enhancing English proficiency and developing self-efficacy among teachers in the secondary schools. The results of this study illustrate the importance of language proficiency as the foundation of teachers’ confidence. Also, teachers’ judgments about their teaching competence influence their effectiveness in teaching. These findings suggest that English proficiency enhancement and self-efficacy development should be considered as means to address issues and problems in language teaching.