This study evaluated the airborne concentrations of fungi in university laboratories, hospital diagnostic laboratories in Seoul. The incubated fungi was identified by lactophenol cotton blue (LPCB) staining method. Variables such as types of ventilation, temperature and relative humidity were investigated to explain laboratory airborne fungal concentrations. A total of 97 air samples were collected from 10 facilities in two institutions. Aspergilus spp., including Aspergilus niger, Aspergillius flavos and Penicillium spp. were found as predominant species. Airborne fungal concentrations ranged from not detected (ND) to 1,890 CFU/$m^3$. Airborne fungal concentrations were high in general-ventilated facilities and in laboratories where relative humidity ( > 60 %) were high ( p < 0.001). Therefore, we suggest that relative humidity should be maintained to properly reduce the concentration of fungal in university and hospital laboratories.