Abstarct: Although lots of studies have been conducted on different techniques of language assessment, a great number of Iranian English teachers are not proficient enough to use them fundamentally. The problem is that what teachers do in classrooms is just teaching and not assessing. Furthermore, very little attention has been paid to teachers’ assessment ways in classrooms. In order to reveal the teachers’ techniques of assessment, this study applied a grounded theory methodology to theorize the teachers’ techniques of assessing four English skills in English classrooms. Participants were selected through purposive sampling and sequentially followed by theoretical sampling. Teachers’ techniques were collected through open-ended interviews. It was found that different techniques of assessment are used in listening, speaking, reading and writing in English classrooms which have clear implications for learners, teachers, syllabus designers, and material developers.