This study aimed to determine the relationship of participation to co-curricular activities on the academic self-efficacy of pupils at Rizal Elementary School, Ledesma St., Iloilo City, for the school year 2015-2016. This study used correlational research. There were two instruments used in the study: to measure the pupils’ participation to co-curricular activities. This was adapted from the study of Emboltorio, Ma. Corazon, et.al., (2000) The Relation Between Co-Curricular Activities and Academic Performance of Intermediate Grade Pupils At WVSU-ILS. The academic self-efficacy instrument was adapted from Morgan-Jinks Self-efficacy Scale. The results showed that when the pupils were classified as a whole group, the participation level to co-curricular activities was low. When the pupils were classified according to sex, both male and female pupils had a low participation. When the pupils were classified according to socio-economic status, the participation level of pupils with low and average socio-economic status was low; however pupils with high socio-economic status had high level of participation to co-curricular activities. The results also showed that as a whole group, the academic self-efficacy was good. Male pupils who had high level of participation to co-curricular activities had a very satisfactory academic self-efficacy while female pupils have a good academic self-efficacy. Pupils with both low and average socio-economic status had very satisfactory academic self-efficacy, and pupils with high socio-economic status had an outstanding academic self-efficacy. Male pupils who had low level of participation to curricular activities had very good academic self-efficacy and female pupils had a good academic self-efficacy. Pupils with low and average socio-economic status had both good academic self-efficacies while pupils with high socio-economic status had a very good academic self-efficacy. Lastly there is no significant relationship between participation to co-curricular activities and academic self-efficacy.