Previous research has found that native English speakers can judge, with a relatively high degree of accuracy, the frequency of words in the English language. However, there has been little investigation of the ability to judge the frequency of high and middle frequency words. Similarly, the accuracy of EFL teachers' frequency judgements remains largely unstudied. This study required two groups of native English speakers (English teaching professionals and undergraduate university students) to judge the frequency of words by ranking two lists of 24 words in order of frequency. The first list covered a wide range of frequency levels and the second list covered words in the middle frequency range. The results from this study indicate that the English teaching professionals' accuracy judgments do not seem to be significantly better than university undergraduates. Furthermore, both groups of native English speakers had difficulty judging the frequency of words in the middle frequency range. These results indicate the need for teachers to consult frequency lists rather than rely solely on their intuitions. (Contains 6 tables.)