Indoor Air Quality degradation is of exceptional concern due to the potential adverse effects indoor air pollutants have on human’s health. Students are a susceptible group of people, who spend a lot of their time within classrooms. The purpose of this study is to investigate the concentration levels of particulate matter (PM) and total airborne fungi, in school classrooms. Further objective is to examine possible correlations between PM10, PM2.5, PM1, ultrafine particles (UFPs, diameter<100 nm), and airborne fungi. The measurements were performed using fully automated instrumentation. The results indicate that a lot of PM10 concentrations exceeded the proposed daily limit of 50μg/m3. Also, in some cases the concentration of the total airborne fungi indoors, exceeded their concentration outdoors. There is evidence that certain correlations exist between PM and airborne fungi.