This study attempted to characterize qualities of an effective English language teacher (EELT) as perceived by Iranian English language teachers and learners. For this purpose, a tailor-made questionnaire was administered to 59 English language teachers and 215 learners of English at universities, high schools and language institutes in Iran. The results indicated significant differences between teachers' and learners' views on some characteristics of EELTs. Teachers seemed to agree more strongly than students that an EELT should assign homework and integrate group activities into the classroom. Other areas of significant difference in opinions included preparing the lesson well, using lesson plans and assessing what students have learned reasonably. Students, on the contrary, agreed more than teachers that teaching English in Persian (first language of the learners) was one of the prominent characteristics of an EELT. The qualitative analysis indicated that teachers perceived the features like mastery of the target language, good knowledge of pedagogy and the use of particular techniques and methods as well as a good personality to make an EELT, whereas, learners gave more weight to characteristics relating to a teacher's personality and the way he behaves toward his students.