This study explores Korean middle and high school English teachers’ assessment literacy (AL) levels, relationships between their years of teaching experiences and AL levels, and the teachers’ perceptions toward school assessments. The total of thirty five Korean English teachers participated in the current study. This study employed a background questionnaire, a survey on teachers’ AL levels, and an open-ended questionnaire asking teachers’ perceptions of school assessments. The results revealed that the teachers at both school levels did not possess sufficient AL levels, and the longer teaching experience did not guarantee the higher AL levels. The findings also demonstrated that the types of assessments were usually controlled by the Korean educational policies, and they often felt pressured in strictly following assessment relevant policies. The overall results hint that teachers need to be provided with ample opportunities of taking training courses or programs to improve their AL levels. Based on the findings further implications are presented for stakeholders in the field of English education.