Bioaerosol is one of the sources that influence poor indoor air quality. Most buildings have air-conditioners (AC) to cool down the indoor building. However, the microorganism tends to grow, especially on the air conditioner filter, which may cause health problems called sick building syndrome and other bacterial diseases. Besides, temperature variation, relative humidity, and human occupancy in the AC building can also influence bioaerosol growth. Staphylococcus and Micrococcus were the most dominant genera detected in the AC building worldwide. Therefore, AC buildings need periodic services to avoid the spread of bioaerosol growth as it leads to adverse indoor air quality and to maintain human health.