Rapid urban growth in low- and middle-income countries brings both opportunities and significant challenges. Addressing traffic congestion, air pollution, and other environmental disamenities requires both improved infrastructure and greater individual protection. In the three chapters of my dissertation, I examine some of the challenges associated with these structural and individual adaptations. In the first chapter, I show how, in Kampala, Uganda, road improvements can have large local and citywide benefits but require the acquisition of private land. The government may not be able to acquire that land at low enough cost in locations where the benefits from road improvements are the largest, threatening the returns on investment for such infrastructure projects. In the second chapter, I focus on a major threat to highly congested sub-Saharan African cities: air pollution. I collect new pollution and firm data to show that, although air pollution in Ugandan cities is unevenly distributed, firms concentrate in the most polluted areas due to the co-location of customers and pollution from traffic. Labor market frictions and misinformation lead to workers being uncompensated for their pollution exposure. In the third chapter, I study the relationship between indoor and outdoor air pollution in Jakarta, Indonesia’s capital city and one of the most polluted cities in the world. I show that average indoor air pollution is higher than average outdoor air pollution because of both a high infiltration rate and prevalent hyperlocal pollution sources like smoking and trash burning. Yet, households underestimate these high indoor pollution levels. Through a randomized controlled trial, I show that experiencing clean indoor air through an air purifier can improve households’ knowledge about indoor air quality and the health costs of indoor air pollution. The intervention also raises high-income households’ willingness to pay for air purifiers.