The whole world is facing various environmental challenges owing to its large human population. As most of the world’s population now lives in urban areas, the pressure on the urban environment has significantly increased. The urban environmental crisis is not new to the world; several cities worldwide have experienced dense smog, solid waste accumulation, water contamination, and poor air quality, both outdoors and indoors. But now, more severe, new challenges are arising due to climate change, the pandemic rise, and the water availability crisis. Ensuring safe potable water, good disaster management, and well-developed health infrastructure are some of the new urban environment challenges. Areas where rapid and unplanned urbanization is taking place are the worst hit by these environmental crises. The magnitude of these crises has significantly increased, necessitating global involvement in formulating effective strategies to address urban pollution in the form of poor air and water quality, noise pollution, and hazardous waste. Physical and psychological health impacts of these crises are the greatest and need immediate response from the stakeholders. Proper monitoring, evaluation, and planning that involve awareness and education among the common people are some of the beginning steps. Availability of enough housing and stringent policies for energy and land use are required to avoid slum formation and maintain sanitation. The enormous amount of resource consumption in urban areas has far-reaching and long-term effects on the natural ecosystem, not only on urban land but outside of it as well. These threatened and deteriorated natural ecosystems are also part of urban environmental challenges. Effective participation from stakeholders for the mitigation of these urban environmental challenges requires knowledge of all aspects. In this chapter, we will be highlighting these urban environmental challenges in detail using some case studies.