The purpose of this study was to assess the challenges and strategies of teaching speaking skills in large classes. To this end, Mettu preparatory school which is found in Ilu Abba Bora Zone, Oromia region is selected. The respondents of the study were four English language teachers and one hundred twenty students from grade eleven. Descriptive survey-which is known as cross-sectional research design was used to describe the current situation of the study, and purposive and simple random sampling techniques were used to select a number of study units from a defined population. The instruments used to collect data were interview and questionnaires. Then the collected data were analyzed using both quantitative and qualitative methods of data analysis. The findings of the study showed that the teachers lacked different classroom management strategies in teaching speaking skills, and most of them could not effectively play their managerial roles during teaching speaking skills in large classes. The findings also showed that the teachers rarely used different strategies and techniques in order to develop students’ speaking skills. The study further revealed that the teachers have considered large classroom as a problematic in teaching speaking skills rather than their teaching methodology. The study also portrayed that students in large classes hardly interact with each other to improve their speaking skills. Furthermore, the study indicated that the teachers frequently used whole class organization at the expense of pair and/or group organizations. Finally, recommendations were forwarded based on the major findings of the study so as to improve the students' speaking skills and use different large class strategies. Hence, it was recommended that English language teachers have to use appropriate strategies to manage large class. Therefore, they must develop the approach that works best for the students based on their learning styles, the characteristics of their students, and the goals and objectives of the lessons.