Background: Fungi are regarded as one of causal factors of respiratory allergies and are a serious threat to public health in indoor environments. Before conclusively identifying fungi as the major causative agent of all or some types of rhinitis, we should have a good knowledge of the fungal flora of the nasal cavity and indoor building environments of healthy subjects. Objectives: The aim of this study was to determine the presence and relative abundance of fungal flora in the nasal cavity and bedroom of healthy subjects in Mashhad city, north east of Iran. Patients and Methods: A group of fifty healthy volunteers without a history of respiratory system diseases were selected. Samples from the nasal cavity and different parts of the bedroom including indoor air, pillow, mattress, blanket, dust of the bed, dust of the shelf and dust of the air duct were collected and cultured. The fungi were identified by standard mycological techniques. Results: The most common fungi isolated from all samples were Aspergillus, Penicillium, Yeast, Alternaria and Cladosporium. Stemphylium, Ulocladium, Stachybotrys, Basidiobolus and Exophiala showed the least frequencies among the isolated fungi. Conclusions:The presence of fungi in the nasal cavity and indoors of healthy subjects in this study suggests that fungi should be considered as health hazards. Furthermore, it is important and seems necessary to monitor indoor air quality and raise awareness of existing threats due to microorganisms, including fungi.