This paper describes the structure of the "Air Pollution Course", an environmental science laboratory course developed at the Science Education Laboratory of the Faculty of Primary Education, University of Athens, as well as the findings resulting from its implementation by pre-service elementary teachers. The course proposed in this study deals with the problem of air pollution, which has a special local interest in a large and crowded city like Athens, Greece. The design of the "Air Pollution Course" was based on a combination of experimental study and the use of educational software. All the activities were carried out with the aid of contemporary technological equipment according to the Microcomputer Based Laboratory and to Information and Communication Technologies principles. This approach has encouraging results to the understanding of the problem of air pollution. The laboratory course has improved pre-service elementary teachers' correct use of terms and accuracy in scientific descriptions. These facts suppose deeper conceptual understanding on air pollution phenomena. However, there is a need for further improvement of the pre-service elementary teachers' knowledge in air pollution phenomena, as they still hold misconceptions. The teaching implications of these results are discussed.