This chapter investigates the microbial air quality of one kampung adjacent to a landfill. Kampung Nambo, with its steep topography, is located less than 300 m from Cipeucang landfill. The landfill has been operated since 2011 and received municipal solid waste from Tangerang Selatan City. The waste decomposition at the landfill produces odors and germs that spread all over the kampung and beyond. Seventy-four houses out of 153 houses in Kampung Nambo were tested. Further investigation is done through a four-quadrant matrix chart and linear regression using the house’s orientation to the landfill, distance from the landfill, elevation compared to the landfill, and cross ventilation as the variables. Outdoor and indoor air flow was simulated through SimScale’s computational fluid dynamic (CFD) modeling software for visualizing the air movement. Finding shows that 67% of the houses have air quality exceeding the limit of the allowed threshold. Secondly, distance from the landfill has the most correlation and impact to the microbial air quality, followed by humidity, orientation, elevation, density, and lastly cross ventilation. This study found that cross ventilation is not easily applicable in houses adjacent to a landfill due to the bad outdoor air quality. Furthermore, barriers such as walls and trees are proven to reduce the level of air pollution in the house.