ABSTRACT This study investigated the purpose, prevalence and attitudes of teachers’ and students’ use of Amharic in English classroom at public and private secondary schools. The study followed a descriptive survey research design. The data were gathered from 120 public and 120 private secondary school students; altogether 240 grade 11 students were selected through simple random sampling method. Likewise 3 grade 11 English language teachers were selected randomly at public schools and 3 grade 11 English language teachers were selected using comprehensive sampling at private schools. In sum, 6 English language teachers were participants of the study. Data were gathered through classroom observation/audio-recording, questionnaire and interview. The qualitative data gained through semi-structured interview and classroom observation were transcribed and described. The quantitative data gained through close-ended questionnaire are presented in a form of table using frequency, percentage, mean and standard deviation; also an inferential statistics, i.e. independent sample T-test was employed to show if the difference is statistically significant or not on the aspect of attitude and prevalence between public and private secondary school teachers and students. Moreover, some figures were employed to show the difference between public and private school teachers’ and students’ L1 use in the aspect of attitude and prevalence. The findings of the study revealed that the public and private school students and teachers had positive attitudes towards L1 use in EFL classrooms. However, even though both public and private school English language teachers and students had positive attitudes towards using L1 in English as a foreign language classrooms, the degree of the public school teachers’ and students’ attitudes were higher than that of the private school teachers’ and students’ attitudes. The findings also revealed that the public and private secondary school English language teachers and students used L1 in EFL classrooms for the same purposes. However, though the purposes were similar, the amount of L1 used for those purposes by the private school students and teachers were low use of L1 and the public school students and teachers were high rate of ceiling L1. The prevalence of Amharic language use in EFL classrooms by public school students and teachers was higher than that of the private school students’ and teachers’ Amharic language use in EFL classrooms. Based on the findings of the study, it is recommended that public school teachers and students should use L1 as a last choice and the public and private secondary school English language teachers should be provided with adequate trainings in classroom language so that they can effectively use the L1 and the target language.