The main purpose of the study was to find out if interest in extra-curricular activities has any influence on self-efficacy with reference to social self-efficacy, academic self-efficacy, language self-efficacy and moral self-efficacy. The ex-post facto design was adopted for the study. A sample of 1,586 students was randomly selected from the public secondary schools in Cross River State for the study. A questionnaire titled "Interest in Extra Curricular Activity and Self-Efficacy (IECASEQ) was the instrument used for data collection. The face validity of the instrument was determined by two experts in test and measurement and two in educational psychology. The reliability of the instrument was determined using Cronbach Alpha reliability method. The data collected were analysed using descriptive statistics. The results revealed that interest in co-curricular activities significantly influenced social self-efficacy, academic self-efficacy, language self-efficacy, moral self-efficacy and overall self-efficacy. Based on the findings of this study, it was recommended among others that teacher and school administrators should create opportunities for students to travel for excursions, and not see involvement in co-curricular activities as a distraction to students.