This descriptive study explored EFL teachers‟ actual classroom MT use. To this end, five EFL teachers who were teaching at grades 9 to 12 were selected for the study based on purposive sampling method; and nine students drawn from grades 9 to 12, selected by snow ball sampling method, participated in the focus group discussion for triangulating the data .The data were gathered through a 343 minutes long classroom observation and an 88 minutes long focus group discussion. Ten English lessons were observed, and one focus group discussion was held. The classroom observation and focus group discussion were all audio video recorded and transcribed for analysis and interpretation. The data captured from the classroom observation were quantitatively analyzed through frequency and percentages, and the data collected from the focus group discussion were qualitatively analyzed. The findings showed that (1) EFL teachers made use of a plethora of MT (30. 25% Amharic) and (69.23% English) in a way that may deskill students by negatively affecting the learning of the FL (English). (2) The study uniquely revealed that 0.52% of the total words uttered by the observed EFL teachers, were intra-word code-mixed: strange phenomena of speech utterances where the EFL teachers added bound Amharic (L1) morphemes to the free English (TL) morphemes. The data collected from the students who participated in the focus group discussion pictured that EFL teachers frequently utilized Amharic in their classes for various purposes with varying degree of use, and they estimated that most EFL teachers‟ L1 use may fall within the range of 50% to 7o%.Furthermore, the study indicated that EFL teachers‟ MT overuse might have emanated from the students‟ poor knowledge of English and from the EFL teachers‟ low level of oral proficiency in the TL. Finally, it is recommended that EFL teachers at Preparatory and General Secondary Schools should make every effort to take their English to a fully competent speaker level, employ visual aids, teach the FL through action and demonstration, use video lessons with attractive methodology, and consider learners‟ proficiency and task difficulty to decide when to use the learners‟ L1 very carefully and systematically to facilitate the teaching and learning of the TL.