Abstract: Poor air quality has profound adverse effects on human health and ecosystems with further negative implications on future generations. Excessive urban air pollution in Ulaanbaatar city poses huge threats to a sustainable development in Mongolia. Worsening air quality problems in Ulaanbaatar city of Mongolia was concerned in this study. The state of air quality in Ulaanbaatar City was updated by reviewing lots of literature. Thereafter, implications for a sustainable development are drawn. Further, the state of the problem in terms of main pollution sources, effects and abatement approaches is compared and contrasted with air pollution cases in history (e.g. London fog of 1952 and Los Angeles photochemical smog) and even with cases in emerging economies of Africa and Asia.