The purpose of this research was to study the knowledge and opinions of secondary school teachers in Bangkok Metropolis concerning environmental pollution. The samples were 100 science teachers and 300 non-science teachers at eight secondary schools in Bangkok Metropolis. Research procedures were as follows: studying the secondary school curriculum and textbooks concerning environmental pollution: constructing a test about environmental knowledge and a questionnaire concerning opinion on environmental pollution. Pre-Testing the knowledge test with the students of certificate of education level in environmental course in order to find discrimination power, degree of difficulty and reliability before administering to the chosen sample. The results revealed that 87 percent of science teachers and 61.33 percent of non-science teachers got the test mark higher than 50 percent in knowledge test. About 67.75 of both science and non-science teachers got higher than 50 percent in the test. The knowledge of science teachers and non-science teachers was significantly different at the level of 0.05. On contrary there is no difference between science teachers and non-science teachers’ opinion concerning the environmental pollution.
