The objective of the research was to compare the porosity/compactness of the knitted structures made from viscose and polyacrylonitrile yarns with incorporated elastane and without elastane, respectively, and to evaluate the elastane addition impact to their moisture management and air permeability properties. The addition of elastane considerably reduces the wettability of the wet relaxed viscose knits, while it moderately increases the wettability of the wet relaxed polyacrylonitrile knits. The polyacrylonitrile knits exhibit distinctively better wickability than comparable viscose knits. When no elastane is added, air permeability is better for viscose knits while with the elastane addition, air permeability is better for polyacrylonitrile knits.