Durable antimicrobial properties could be achieved on acrilan fabrics by chemically incorporating biocidal quaternary ammonium salts such as cetylpyridinium chloride (CPC) into the fibers. The chemical interactions between CPC and acrilan fibers were investigated through adsorption isotherm and exhaustion rates of CPC on the fabrics under various conditions. The equilibrium adsorption of CPC on the acrilan fabrics was in good agreement with the Langmuir adsorption isotherm. The study found that CPC concentration, pH value, and finishing temperature and time affected the adsorption process and antimicrobial properties of the acrilan fabrics.