This study investigated levels of airborne bacteria in 90 indoor sampling sites with no known complaints such as kindergartens, schools, homes and dorms over three seasons. Airborne bacteria samples were collected before and during the heating season in Canakkale, Turkey. Also, a detailed occupant questionnaire was completed by one of the occupants (n=90) in each sampling site. Total bacteria counts (TBCs) were found to be higher in the sampling sites where coal was used as a heating source and in kindergartens where the occupancy rate was highest (p<0.05). Meteorological parameters were associated with outdoor TBC levels (p<0.001). Associations were found (p=0.05) for indoor TBC and other building factors (last floor covering/wall painting/renovation times, heating/cooking fuels and the age of the building). Indoor TBC levels together with the building-related factors (environmental tobacco smoke exposure, occupancy rate, distance to traffic, heating fuel, amount of carpet covering, and last wall painting time) and personal factors (gender and daily time spent indoors) were found to be associated with at least one group of the sick building syndrome (SBS) symptoms (p<0.05). In particular, general SBS symptoms (headache, fatigue and dizziness) were observed more often in female participants (p<0.05). In conclusion, there is a need to conduct more studies in larger populations to find the links between air pollutants and SBS symptoms.