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Background: The aim of the present study was to determine the response of lung function indices to aerobic and anaerobic exercises in polluted air. Materials and Methods: In this quasi-experimental study, 20 healthy men were randomly divided into two equal groups experiment and control. The experiment group initially had one session of aerobic exercise and after a three-week break, received one session of anaerobic exercise on ergometer bicycle in polluted air. The control group did the same kind of exercise in healthy clean air. Lung function tests were run before, right after (the first post-test), and 24 hours after the exercises (the second post-test). Results: Aerobic exercise in unhealthy polluted air resulted in the significant reduction of FEV1, FVC, and FEF25-75% indices in the first and second post-tests. Following anaerobic exercises in polluted air, a significant decrease was observed in FVC and FEF25-75% indices in both the first and second post-tests. FEV1 and FEF25-75% indices in the first and second post-tests, and FEV1 and FVC indexes in the second post-tests underwent a remarkably greater reduction following aerobic exercise. Conclusion: While aerobic physical exercise in polluted air caused a reduction in the lung function indices (FEV1, FVC and FEF25-75%) in the first and second post-tests, it seemed that anaerobic exercises in polluted air induced a significantly smaller reduction in FEV1 and FEF25-75% in the first and second post tests, and FEV1/FVC in the second post test.