In the presented research, the main aim is to investigate the antibacterial effectiveness of BAC solutions on acrylic fibers used in machinery carpet. An acrylic pile carpet laid in a public place for 30 days and the existence of some microbes were investigated on it. The antimicrobial effect of different BAC solutions for identified microbes was studied in vitro. The acrylic fibers were treated with the same different solutions of BAC as before and the antibacterial effectiveness was assessed by the zone of inhibition method in different times. Two pieces of carpet untreated and treated with BAC solution sewed together and laid for one week in the public place and the amounts of bacterial growth determined by colony count method and the results compared. Finally some mechanical properties of treated acrylic fibers measured after 30 days and compared with untreated one. The results showed the presence of some pathogenic microbes on the laid carpet such as Escherichia coli and Staphylococcus aureus. The inhalation time for treated acrylic fibers improved. The amount of colony growth on treated carpet reduced considerably and besides the mechanical tests results showed no significant deterioration effect of studied properties in comparing with untreated yarn.