Beliefs of in-service English teachers about grammar learning/teaching and the influence of such beliefs on their classroom practices remain relatively unexplored. More precisely, this study explores English teachers' beliefs about grammar learning and teaching. It throws light on the teachers' actual practices in the classrooms of 7th -12th grades, at several schools of Hodeidah. The main instrument of this study is the questionnaire used to collect data on teachers' beliefs and their teaching procedures in classrooms. It is administered to 80 teachers of 12 primary and secondary schools. Non-participatory classroom-observations are also made to back up the main data. It is found that teachers do possess a set of complex beliefs about learning and teaching grammar that are likely to be derived from their prior experience of teaching English. These beliefs are correlated with the suggested strategies used to teach grammar as correlation is significant at the 0.05 level though observations have shown that beliefs are not actually reflected in the classroom practices.Eventually, implications of this study are identified for effective teaching of grammar.