Airborne microbial contamination was collected from the main directions of the holly mosque (Al-Haram mosque), Makkah city, by using the gravitational method. Bacteria, fungi and actinomycete concentrations ranged between 1470– 21800 CFU/m3; 44 - 572 CFU/m3, and 0.0 - 264 CFU/m3, respectively at all directions. Bacterial concentrations significantly differed between directions, and Gram positive bacteria constituted ~ 90-100% of the total bacterial isolates. Gammaproteobacteria were the common Gram negative bacteria, and Aspergillus was the predominant fungal genera. Mesophilic bacteria negatively related (P< 0.05) with relative humidity. Human activities had more effective influence on the microbial concentrations than the meteorological factors.
