The purpose of the research paper was to investigate the effect of eclectic learning approach on the academic achievement and retention of students in English at elementary level. A sample of forty students of 8th grade randomly selected from Government Boys High School Khurram District Karak was used. It was an experimental study and that's why sample subjects were classified into two equal groups on the basis of pre-test scores. For data collection, pre-test post-test equivalent groups designed was used. Descriptive statistics i.e., mean, standard deviation and inferential statistics i.e., t-test were employed for analyzing the data. After analyzing the data, it was come to light that eclectic learning approach has a positive effect on students' academic achievement and retention. Eclectic learning approach was found more productive, effective and successful in teaching of English as compared to traditional learning approach at elementary level. So, eclectic learning approach should be adopted by the teachers for improving students' performance in English at elementary level.