The aim of the study is to determine the knowledge level of pre-service elementary science teachers about the components of air pollution, pollutants, the effects of air pollution on human health, the relationship between air pollution and acid rain and the greenhouse effect, and the precautions to be taken against air pollution. In the study, the 49 item survey which had been used by Yeung, Boyes & Stanisstreet were translated into Turkish and then subjected to 345 pre-service teachers studying in grades 1, 2, 3 and 4 at Ondokuz Mays University, Education Faculty, Elementary Science Teaching Department. The collected data were analysed through SPSS package program. It was seen that there are some pre-service teachers in all the grades who know wrong that more oxygen exist in fresh air than nitrogen according to the results of the study. In the light of the answers to the item in the survey regarding the existence of nitrogen in fresh air, it was seen that some pre-service teachers had no idea, but this decreased as their grade increased. It was seen that there were some pre-service teachers who had no idea about the relationship between air pollution, acid rain and the greenhouse effect. The answers of the students to the questions as to what measures could be taken to reduce air pollution showed that especially heavy fines and legal obligations are acceptable. It is significant that pre-service teachers in every grades has marked the choice "a little" for the item "How much do you know about air pollution?"; however, the study revealed that they are worried about air pollution.